Mike Munchak's departure from the Steelers to the Broncos won't make an immediate impact on the organization, but could be felt over time. In 2018, the Steelers offensive line was one of, if not the most, consistent unit in the NFL, and they still have the players to be great in 2019.
But without Munchak, keeping this unit at an elite level could require more of an investment in free agency and the draft. Let's take a deep dive into how his work with the offensive line has boosted the rest of the team over the years, as well as grade the offensive line's 2018 season:
The Steelers' offensive line has been anchored by its best players: Maurkice Pouncey, David DeCastro and Marcus Gilbert. While Gilbert has been hurt most of the past two seasons, he still is one of the Steelers' best players on offense when healthy.
They also represent the Steelers only real draft investment into the unit since 2010. Both Pouncey and DeCastro were drafted in the first round and Gilbert was drafted in the second. The only other linemen drafted in the top three rounds in that time were Mike Adams and rookie Chukwuma Okorafor.
That means that their left tackle, a position many agree is the most important on an offensive line, their left guard and all their backups have been added using minimal investments. While Kelvin Beachum and Ramon Foster were both on the team when Munchak arrived in 2014, the Steelers have needed hundreds of snaps from several undrafted players like Alejandro Villanueva, B.J. Finney, Chris Hubbard and Matt Feiler to survive. Each has played to a level where the Steelers haven't needed to make a big move in free agency or invest high in the draft, which has allowed the Steelers to focus on rebuilding other position groups.
Kevin Colbert and Mike Tomlin have had 17 picks in the top three rounds since 2014, and only one of them, Okorafor, was used on the offensive line. Among the players picked with those groups were, Ryan Shazier, Stephon Tuitt, Bud Dupree, Sean Davis, Javon Hargrave, T.J. Watt, JuJu Smith-Schuster and Terrell Edmunds.
That's eight starters that have largely helped the defense. While there have also been picks that haven't worked out like Artie Burns, Senquez Golson, Dri Archer and Sammie Coates, there are also players that could prove more valuable to the team soon, namely Cameron Sutton and James Washington.
Not all their picks have worked, but Munchak has taken several linemen on whom the team has spent virtually no draft capital or cap dollars to acquire, and made them extremely reliable.
The 2019 Steelers will still have Pouncey, DeCastro and Villanueva to lean on and should be among the NFL's best again. They also still have Finney to replace Foster, should he leave, and Feiler to replace Gilbert, should he leave or be hurt again.
But the real question is about their future. With Shaun Sarrett as the new line coach, can he make magic out of players drafted from the bottom rounds or overlooked altogether? The answer will determine if the Steelers can continue to build towards their future. If they don't have similar success, that could force them to invest in the offensive line sooner rather than later, which could impede their search for top defensive talent at cornerback, inside linebacker, or even replacing Antonio Brown.
Final Grades
Here's how these will work: We will grade each unit on the team and display how the players did through each quarter of the season, with each quarter represented by four games. Our War Room series has graded players on our stars and skulls system, so it's time to add them all up and show their final marks.
Each game was graded on this scale:
Had a big play or a decent game 
Very impressive, multiple big plays
Elite performance
Gave up a big play without redemption 
Total performance was a disappointment
Horrible, inexcusable
If a player was average or unremarkable, they received no mark for that game. We have tallied all their performances to see who was the top of the class.
Valedictorian: David DeCastro
First Quarter: 1 0 2 Games
Second Quarter: 120 4 Games
Third Quarter: 110 4 Games
Fourth Quarter: 70 4 Games
Final Marks: 310 A+
Best Game: Week 9 at Ravens
Worst Game: Week 4 vs. Ravens
DeCastro earned the top marks among the group. He never had a bad game and impacted almost every game he played. He never appears to be the vocal leader of the group, but he's always an enforcer up front. DeCastro was always in his spot in pass coverage, but he was most dangerous as a lead blocker in the run game.
James Conner thrived whenever the Steelers used a lead blocker in run schemes, and especially when that player was DeCastro. Here's a prime example when he took on Myles Garrett and eliminated the Browns' best defensive player to open up Conner for a huge gain:
He's arguably the best guard in the NFL, even though he wasn't recognized on the AP All-Pro team. He will continue to be a staple of the offense in 2019 and is a huge reason why Munchak's departure won't have an immediate impact on the unit's performance.
Maurkice Pouncey
First Quarter: 2 0 4 Games
Second Quarter: 120 4 Games
Third Quarter: 110 4 Games
Fourth Quarter: 71 4 Games
Final Marks: 321 A+
Best Game: Week 9 at Ravens
Worst Game: Week 14 at Raiders
Pouncey had the same differential as DeCastro when it came to stars and skulls, but he wasn't the valedictorian because of his one skull against the Raiders. Still, he's just as vital to the line's continuity in 2019 as DeCastro. He's a dominating figure in the middle and can pull to be a great lead blocker. When that comes from a center, it adds important dynamics to an offense.
Here he pulls with DeCastro in the Steelers' win in Cincinnati. DeCastro gets the first man, while Pouncey is athletic enough to get all the way out to the edge and take out Dre Kirkpatrick:
So long as Pouncey and DeCastro are part of the line for the next three seasons, this unit will have a strong foundation.
Alejandro Villanueva
First Quarter: 1 2 4 Games
Second Quarter: 110 4 Games
Third Quarter: 81 4 Games
Fourth Quarter: 100 4 Games
Final Marks: 30 3 A
Best Game: Week 8 at Browns
Worst Game: Week 1 at Browns
Villanueva is the prime example of Munchak's impact on the team. An undrafted prospect that never played left tackle has been turned into one of the team's most reliable players. Typically I have always had tough grades on Villanueva to start off seasons because he traditionally starts slow and finishes strong. While he wasn't elite to start this season, he wasn't horrible either.
And after the team's loss to the Ravens in week four, Villanueva caught fire. He was great as a run blocker and this was arguably his most impressive season in pass protection.
Here he dominates Terrell Suggs when the Steelers won the rematch with the Ravens at M&T Bank Stadium. Suggs may be old, but he's wily and knows plenty of tricks to win edge battles. Watch how he tries to set up Villanueva by faking to go outside, then tries to use a rip move to Villanueva's inside shoulder. Villanueva shuts it down, and when Suggs tries to counter the Pro Bowl left tackle smothers him:
Before this season I saw Villanueva as a good asset, but if he follows up next season with similar play to his 2018, he could become just as important to the line as DeCastro and Pouncey.
Ramon Foster
First Quarter: 5 0 4 Games
Second Quarter: 80 4 Games
Third Quarter: 50 4 Games
Fourth Quarter: 71 4 Games
Final Marks: 251 A-
Best Game: Week 9 at Ravens
Worst Game: Week 6 at Bengals
At 33 years old, he's the eldest of the Steelers' linemen. He's also a key communicator who maintains the integrity of the middle of the line, picking up stunts and ensuring each player is on the right assignment in run blocking schemes.
Watch how he's able to work with Pouncey to chip from the defensive tackle and seal the inside linebacker to give Conner the lane to accelerate into the Browns' secondary. He shoves his man to the inside and keeps his feet chopping, but by the time the linebacker realizes where the play is going, Foster's there to wall him off:
It's highly likely Foster gets a huge payday from another team in need of an experienced guard and that the Steelers won't be able to afford him. But he's made a huge impact on the team over the years as a consistent contributor and has the respect of the locker room.
Matt Feiler
First Quarter: 0 0 1 Game
Second Quarter: 40 2 Games
Third Quarter: 32 4 Games
Fourth Quarter: 72 4 Games
Final Marks: 144 B-
Best Game: Week 16 at Saints
Worst Game: Week 11 at Jaguars
Feiler is the first of the backups we'll discuss because he saw action in 11 games this season. He wasn't the imposing force that Gilbert is, but he was more than adequate. He would occasionally get beat by a prime pass-rusher like the Jaguars' Yannick Ngakoue, but he was never the revolving door that some backup tackles are in today's NFL.
He was plenty physical, too, in the ground game. Here he is shoving Carolina's No. 92, Vernon Butler, a first round pick from 2016, down the line in a goal line situation. He gets Butler's outside shoulder and uses good footwork to get into position to create the seal that allows Conner the space to plunge in for the score:
The Steelers still have rights to Feiler for 2019 and will keep him. He proved reliable as a backup and if he has another positive season, could become a highly valued unrestricted free agent in 2020.
Marcus Gilbert
First Quarter: 3 0 3 Games
Second Quarter: 60 2 Games
Third Quarter: 00 0 Games
Fourth Quarter: 00 0 Games
Final Marks: 90 B-
Best Game: Week 5 vs Falcons
Worst Game: Week 1 a Browns
When Gilbert plays, the entire offense gets a boost and defenses have to work a lot harder to win on his edge at right tackle. But availability is the best ability, and missing 11 games was a problem. While there's speculation the Steelers may move on from Gilbert because of his $6.6 million cap hit in 2019 — the Steelers could save on $4.7 million if he's cut before June 1 — I doubt the Steelers let him go.
He's had some bad luck with injuries, but Gilbert is a great talent and having him back could help re-establish the Steelers as a serious threat on the ground in 2019, after finishing 31st in rushing yards and 24th in yards per carry.
B.J. Finney
First Quarter: 3 0 3 Games
Second Quarter: 00 2 Games
Third Quarter: 00 1 Game
Fourth Quarter: 00 0 Games
Final Marks: 30 C+
Best Game: Week 3 at Buccaneers
Worst Game: Week 2 vs Chiefs
Only called upon for six games, and minimally so in most of them, Finney was solid in his spot. The Steelers should feel comfortable with him replacing Foster next year.
Chukwuma Okorafor
First Quarter: 0 0 3 Games
Second Quarter: 00 3 Games
Third Quarter: 20 4 Games
Fourth Quarter: 00 2 Games
Final Marks: 20 C+
Best Game: Week 12 at Broncos
Worst Game: Week 3 at Buccaneers
Solid season for the rookie as the extra lineman in heavy packages and a strong showing in his one replacement game when he faced Von Miller and only allowed a single sack. If he continues to develop, he could be a huge part of the next generation of this unit.
Offensive Line Final Grade: A-
First Quarter Average: B+
Second Quarter Average: A+
Third Quarter Average: A+
Fourth Quarter Average: B+
Much like 2017, the offensive line didn't look at its best to start the season. While they weren't bad, they weren't the dominating bunch the Steelers needed in the early games. All that changed after the team's loss to the Ravens in week four.
They graded as an A+ for five straight weeks, spanning from the week five win against the Falcons to the blowout over the Panthers in week 10. As a unit, they're extremely consistent and have the depth behind the starters to address a few injury concerns.
They'll need to add to that in 2019 if Foster leaves and Finney becomes a starter, especially considering Finney was their only backup center and the immediate replacement for both Foster and DeCastro.
But that's a minor concern compared to the team's other positional needs. The Steelers can bank that this will be a top-ranked unit in 2019, thanks to their solid additions and the house that Munchak built.
