Carter's Classroom final grades: The secondary

After years of having to pick through drafts looking for answers, the Steelers appear to finally have the pieces to build a talented secondary. Rookies Sean Davis and Artie Burns earned their keep in the starting lineup by season's end.

Davis saw more opportunities earlier in the season but was eventually relegated to backup duties before being inserted as a starter for good. He proved to be an asset in run support and in pass defense.

Burns recorded three interceptions, tying for the most by a cornerback in a season during the Mike Tomlin era. He also had the second-most passes defensed on the team.



ARTIE BURNS

Burns' college tape showed a fast player who could change directions quickly with solid footwork. That's what the Steelers got out of him immediately, but there are many other pieces to playing well as a cornerback in the NFL.

Fortunately for the Steelers, Burns embraced his opportunity to start and showed that he can be useful in more than just one aspect of his game.

Strengths: From the many things that translated over from the Dick LeBeau era of Steelers' defense into the Keith Butler era, it's that the Steelers value cornerbacks who can tackle consistently to limit yards after catch.

Burns fit that bill extremely well in 2016, leading all cornerbacks with 51 tackles.

Part of that is how he was consistent in getting to his spot and breaking down into a solid defensive stance to make a fundamental tackle, instead of just trying to chase down opponents and dive after them.

Watch how he blows up this pass to Rashad Jennings in the flat. Normally, a cornerback would be in a rough spot against a running back in space like this, but Burns handles it like a seasoned veteran:



His wide stance shows Jennings that he's not going to guess which way Jennings is going and isn't afraid of any moves Jennings might put on. Burns exhibited these kind of fundamentals consistently throughout the season.

Burns rarely, if ever, found himself crossed up while playing against a route. Fluidity at the hips isn't something that will show up on a stat sheet or something that stands out to fans from the combine, but it's absolutely something that coaches look for in a player.

Burns combines good footwork with fluid hips when he runs with receivers, making him extremely difficult to shake off with a double move.

Watch how he runs with Mike Wallace on this play. Wallace makes a solid cut to the outside, while Burns stays in position to protect the seam then immediately breaks on the Wallace's move:



Burns  prepares himself to pass off Wallace to the safety should the route be a fly pattern, but as soon as Wallace breaks to the sideline, Burns turns and runs with him, creating a very tight window for Joe Flacco to fit the ball.

If you're thinking that play doesn't show enough because that's just Wallace, Burns did it all season against better receivers, including Odell Beckham Jr.

Watch how Beckham Jr. puts on this solid double move in the red zone, forcing Burns to commit early and then have to double back to the corner of the end zone:



Watch how Burns never settles on the underneath setup and keeps his feet shuffling so that when he's ready to break on the deep pattern he has no problem accelerating to run with Beckham Jr. He also has the wherewithal to never engage Beckham Jr. in contact and puts his hand up just in time to make sure the ball won't be caught.

Weaknesses: While Burns' footwork, hips and speed are all great assets, he still has a lot to learn in the NFL.

One of the major things that I saw was that he's very reluctant to use his hands at the line of scrimmage to help him gain leverage on receivers. He's not as physical as he should be, at times, and that comes back to bite him for big plays.

Take the touchdown he gave up to Wallace as an example; when Wallace crossed his face and the perfect pass from Flacco led to the longest touchdown pass in Ravens' history:



When playing this tight against a speedy receiver, Burns could use his hands at the line of scrimmage to disrupt the timing of the receiver and/or help direct them into a more favorable position to be covered. Instead, Wallace gets a clean release, and while Burns does run with Wallace, a missed tackle in open space can often lead to big plays like this one.

Value: Anytime you get a rookie who can consistently start on defense and can be an asset, that's a great win for the front office. He still has plenty of skills to develop, but his early NFL tape suggests that he's a very coachable player whom Carnell Lake will be able to mold.

But what Burns showed throughout the season were not "flash in a pan" sort of moments that can be isolated to specific moments, but rather a track record of the kind of mechanics you want to see from young defensive backs who can lead to them to developing long successful NFL careers.

ROSS COCKRELL

Sometimes luck strikes when you make moves in free agency in places you never could have expected. When the Steelers acquired Cockrell after he was cut by the Bills, they got a starter who could matchup with top-tier wide receivers and run with the best of them.

Cockrell showed that his first year with the Steelers was not a fluke in 2015 and followed it up with another solid season this year.

Strengths: Cockrell is a player who isn't as fast as Burns, but he exhibits plenty of the things you want out of your cornerback. When he has to, he engages with wide receivers at close range and knows how to establish leverage with his hands at the line of scrimmage, limiting the directions the receiver can effectively run and making the job easier for him to keep up with any moves they make.

Cockrell doesn't just keep up with them, he makes plays on the ball in tight situations. The way he can win in tight spaces and get physical with receivers is part of what Burns' game lacked during his rookie year.

Watch how Cockrell works against A.J. Green on this play, breaking up a pass over the middle:



That's not the first time, nor was it the last, that Cockrell has been able to shut down Green in coverage. Even last season the Steelers could count on Cockrell to cover Green in the red zone to provide shut down coverage. The very next play after the one we just reviewed was another pass to Green, which was also incomplete with Cockrell covering him no matter where he lined up.

Weaknesses: While Cockrell does a good job in breaking up passes, he has not shown the ability to make a play on the ball for an interception. Numerous times he has put himself in the right position to make a game changing interception, but he either mistimes his jump, loses focus or just drops the ball.

While he's not as fast or as big as Ike Taylor was of a cornerback for the Steelers, Cockrell does seem to share his lack of an ability to seal the deal on interceptions.

Value: Cockrell is up for a contract renewal during this offseason and is on the list of priorities for the team to keep around after the obvious needs like Le'Veon Bell, Antonio Brown and Lawrence Timmons.

The Steelers finally have, at least, two players whom they can feel comfortable starting at cornerback and matching up with the talented wide receivers that are all around the NFL. Burns has potential to be the star, but Cockrell is setting himself to be a solid part of the mix.

What increases the value of Cockrell is if the team can manage to sign him to a friendly deal. He's not a highlight reel kind of player whom teams would chase in free agency, yet he seems to have found a steady pace of success in the Steelers' secondary. Both sides shouldn't have a hard time finding mutual ground to work out a deal.

WILLIAM GAY

The oldest member of the secondary, and only one remaining from the Steelers' last Super Bowl victory, is William Gay. Last season Gay made NFL history when he took his fifth consecutive interception back for a touchdown. While all those did not come in the same year, it was still an impressive feat.

Gay represents the initial work Lake put in as a position coach in which he inherited a secondary that was already aged and was not receiving and top-tier investments from free agency or the draft. He turned from being one of the biggest liabilities on defense in 2010 to becoming a leader for the secondary and arguably its most knowledgeable player by 2014.

Strengths: The reason Gay has been able to stay with the Steelers for so long is that he's made sure to be one of their most reliable men in coverage assignments. Often the Steelers could see players like Antwon Blake not finishing their assignments, overplaying one part of their zone or forgetting their place in the scheme altogether.

But not Gay, and that was also the case this season. Gay was the slot man once the team became confident the skills of Burns on the outside, primarily because they could rely on him to switch from man to zone assignments on the fly more so than his young counterparts.

Weaknesses: However the Steelers also saw what comes with age in the deterioration of Gay's athleticism. Gay used to be able to run with quicker receivers more with his speed and quickness, but as the season rolled on in 2016 opponents began to recognize that he wasn't the same player.

Take a look at this matchup in the AFC Championship Game against Julian Edelman. Gay is locked in man coverage and is able to keep up with Edelman to stay around, but he is ultimately brushed off with a simple double move:



I firmly believe the Steelers knew that this would be a problem if they tried to press and play bump-and-run style of coverage against the Patriots and that with their best receiver being Edelman, a slot-expert, they figured their best bet would be to build their defensive foundation in zone coverage.

While what they decided still didn't work out, you can see why they might've been uncomfortable switching to what many analysts thought would work.

Value: Gay is on the books with the Steelers for the next two seasons taking up $2.6 million in cap space next year and $2.3 million in 2018. While that does keep a veteran around for the Steelers who knows their system and can play at any cornerback position while knowing his role, it's tough price to pay for a player who might not see much of the field unless due to injuries.

If Senquez Golson can finally get healthy and be the ball-hawking slot cornerback he was drafted to be, that leaves Gay as the odd man out for the rotation of defensive backs. Whether the Steelers will feel spending the money on Gay for the next two seasons is still a question that might favor Gay.

Cutting Gay now would only free up about $1.3 million in cap space for the upcoming season and $1.75 million in 2018. The Steelers know that Gay is a player whom they can count on to be able to fill-in for a spot in case of an injury to any of their starting cornerbacks, which is Gay's biggest commodity in the twilight of his NFL career.

Considering the frequency of injuries around the NFL and how the Steelers' depth has been tested at multiple positions in each of the past seasons, it would make sense to keep Gay around at least for next season until another dependable player can be worked into the mix.

MIKE MITCHELL

While Mitchell has faced considerable criticism in the past few seasons, he has become a very reliable player. He reads the eyes of quarterbacks well, is consistent at playing his role in the team's scheme, hits strong and is still able to break on the ball quickly.

Strengths: While it won't show up all over a stat sheet, Mitchell does a lot of very good things in the secondary that won't get him noticed by fans. Part of that is playing your assignment well, and when you do that, more often than not you won't get tested by a quarterback very often.

Take this play he made against the Giants for example:



Mitchell plays his zone perfectly to break up the pass. Cockrell's assignment was to not get beat deep on the play, essentially conceding an underneath pattern to Beckham Jr. Mitchell is playing an underneath zone, which allows him to read the eyes of Eli Manning and make a play on the ball.

We couldn't just talk about Mitchell without highlighting some of his hitting skills, so we took a look back at this fourth down stop he helped the Steelers seal off with his hit in the end zone:



Mitchell has refined his hitting skills the past few seasons, lowering his pad level to meet defenders with his shoulder to their chest. He still goes for the knockout hits, but the Steelers' defense needs an enforcer in the secondary to bring hits like this to seal he deal.

But what I think is the biggest asset Mitchell brings is the discipline he displays when he's playing center-field as a safety in coverage. Like the broken-up pass we highlighted against the Giants, you can see on the play below how Mitchell is basing his moves on his reading of the quarterback.

Take a look at this play a few times to see just when Mitchell breaks on the pass. He's the furthest defensive back in the Steelers' defense playing in the middle of the field:



Notice how he shades to the side which Scott Tolzien is looking, but doesn't break on the ball until the very last second. That makes it harder for Tolzien to find an open receiver, and once Mitchell breaks on the ball, he makes a solid play to intercept the pass.

While many people might criticize Mitchell for how excited he gets after an incomplete pass or other aesthetic things they don't like, the tape doesn't lie to show that Mitchell is a solid player whom the Steelers can use in their team.

Weaknesses: The biggest knock on Mitchell is that he still does get overly aggressive, at times, especially against the run. That's what Tom Brady and the Patriots saw, and that led to their flea-flicker call when they fooled Mitchell to come out of position for an easy touchdown.

Value: Mitchell sits at a comfortable position with the Steelers, having proven to be a valuable player in the defense for at least the past two seasons and still having two years left on the contract.

What could lead to some front office talk is the amount of cap space he takes up, which is around $8.1 million, the sixth highest at the moment for 2017. His original deal was heavy on the back-end, but now that he's made it there, he, at least, has another year before he has to consider being re-signed or restructured.

That's because the most money the Steelers will get back toward their salary cap if he's gone for next season is $1.8 million, a waste of money to get rid of your best safety. However that savings number jumps up to $5 million in 2018, which could be the biggest factor to the Steelers and Mitchell working out an extension before 2018.

SEAN DAVIS

The second-round draft pick from Maryland took half a season to earn his keep as a starter, but he certainly maintained it once he got acclimated to being a safety in the Steelers' defense. Davis showed the ability to be effective lining up at various points on the field, blitzing quarterbacks, stopping the run, defending short passes and being responsible for deep coverage.

It's impressive, and a great sign moving forward.

Strengths: I started really noticing the importance of Davis when the Steelers started to employ him at different parts of the field. That showed they felt comfortable with Davis knowing the various responsibilities that come with different positions on the field.

That's great when you get that from a player like Gay, but it's flat-out amazing when a rookie steps in and does it.

Watch how Davis comes from the cornerback spot on the field to contain Ezekiell Elliot on the edge and force a fourth down after a third-and-two situation:



Not only does Davis come quick off the edge, but he breaks down at the exact right moment to force Elliott to the inside. Once Elliott gives up on getting the edge, Davis can make a form tackle and end the play.

Davis' speed comes into play with whatever position he lines up in for the Steelers. He ran the same 40 yard dash time as Burns in the 2016 NFL Combine, a 4.46. Combine that with a level head playing in the middle of the field and you have a dangerous player who can be effective at multiple levels.

Watch how he plays Tolzien in this third and goal situation:



Davis starts off playing his zone responsibility, watching for the run then searching for any tight ends or running backs who might leak into the end zone. Once he realizes that the only receiving threat is covered by Robert Golden, Davis assesses the situation quickly.

Tolzien broke contain when Arthur Moats allowed himself to be sealed to the inside. That forced Davis up to the goal line, where he gets in front of the end zone and breaks down into a solid stance to deliver a blow all before Tolzien can even get to the four yard-line.

Davis looks to be a player whom that the Steelers can turn into an X-factor type of guy in the secondary which they line up at various parts of the field.

Weaknesses: The two things I noticed about Davis were his rookie mistakes in assignments and his lack of big plays. Of course, those are kind of minute when you consider that he's a rookie, but still relevant to his development.

Watch what happens when the Steelers gave Davis deep safety responsibility against the Patriots earlier in the season:



Rob Gronkowski gets matched up with Golden, whom is taller than the Steelers' backup safety by several inches. Davis sees Gronkowski coming over the middle but breaks outside and leaves Golden exposed over the top by the Patriots' top weapon.

Those kind of mistakes decreased over the season, but the Steelers also didn't see too many splash plays from Davis either. He did have an interception on a bad pass from Manning on a fourth-down play against the Giants, but most of Davis' highlights were solid tackles and being in the right spot rather than making game-changing plays on the ball.

Value: Davis' lack of big plays and rookie mistakes is perfectly acceptable at this point in his career. Davis is the prototype of what teams look for in a safety in the NFL. He's 6-foot-1 and fast enough to chase down speedy receivers and backs, all while having a solid football IQ to make plays when given a considerable amount of responsibility.

The Steelers may have the pillars of a great secondary in the coming years in both Davis and Burns if they progress going into the next few seasons.

ROBERT GOLDEN

A player who has worked his way to a spot on the roster showed that he was able to be a solid replacement guy at safety. Last year he showed to be a solid depth player for the Steelers which they could call on in a pinch and give them some good reps at safety. This year, he was called in quickly as Davis was working his way to starter status.

Strengths: The experience Golden gained last season proved fruitful as he was often in the right place at the right time toward the end of the year and wasn't a major liability when on the field. That carried over into the early parts of 2016 and got him early chances to make a name for himself.

When Golden was part of the Steelers' scheme more often, you often saw him playing in the right zone or coming up just in time for run support. Though he's a smaller safety, having someone like that which you can call on to give Mitchell or Davis a break, both being players that the Steelers line up at different parts of the field, makes for a solid depth asset.

Weaknesses: The problem is that it's not good enough to just be a non-liability. The Steelers need a playmaker at safety or at least someone whose athleticism can pose a threat to offenses and make them think more about how to deal with a player who can be considered a weapon in the secondary.

That's not what Golden is for the Steelers. He is solid at playing zone responsibilities and filling gaps in run support, but when matched up against a talented receiver or tight end, he has a hard time being effective.

In addition, whatever chemistry Golden developed with Mitchell in the secondary seemed lost when Golden started to see more snaps after a hiatus when Davis took over the starting role. Communication is one of the biggest keys to a defense and was arguably the best factor to Golden getting more responsibility in the defense initially, but against the Patriots, you saw more breakdowns and mental mistakes, hinting that Golden needs to stay warm to be good.

Value: Ultimately Golden is still a solid depth player to call on and fill in holes, but he has to work on improving in his mental repetitions and minimize his mistakes to maintain his position. Golden is only 26, and his contract has him taking up almost $1.9 million in cap space for the next two seasons.

If he can reduce those mistakes and earn more of the trust of the Steelers, he might land himself a contract like Darrius Heyward-Bey that guarantees him job security inside a system he's familiar with.

JORDAN DANGERFIELD

Jordan Dangerfield was a major surprise early in the season when he was forced into a starting role due to injuries and was a decent addition to the secondary. He wasn't being embarrassed and, despite being a third-string player, actually got involved now and then.

Strengths: Dangerfield isn't a supreme athlete or a large player, but he showed to be a player who could play within the scheme and fulfill a role. He didn't over-commit on plays, and he didn't make major mental errors or bone-headed mistakes to hurt the defense.

Out of a third-string guy, that's acceptable.

Weaknesses: His weaknesses are the reason why he's a third-string safety; he's not fast, not a big hitter and doesn't do anything exceptionally well.

Value: The thing is though, the Steelers don't need someone to be exceptionally well at that position. Just do your job to the point that you're not a liability. Dangerfield is only costing the Steelers a half million in cap space, giving him decent stock to keep his spot on the roster for next season so long as he doesn't have a collapse.

SHAMARKO THOMAS

I'm not going to get into breaking down the strengths and weaknesses of Shamarko Thomas. I'm just going to explain that over an entire season when he was in his contract year, Thomas saw a total of five defensive snaps while players like Golden and Dangerfield, undrafted talent, got starts and considerable playing time in front of him.

That tells me the Steelers are ready to let Thomas go into free agency this season.

OVERVIEW

What the Steelers have in the secondary is a group of young players who are playing fast but not to the point that they surrender their mechanics. The more I watched them this season, the more I could see the solid foundation of coaching techniques that Lake has been pushing upon them.

The unit that has been the goat for this team for so long, really looks like it's a year or two away from being one of its best features.

The Steelers should still look to get younger in the draft, maybe picking up a safety in the third round or so for depth and as a potential replacement for Mitchell in the long run. They could also use another cornerback who isn't coming off the practice squad with the ever-present question of Golson's health and Gay's age being a factor.