INDIANAPOLIS — The Indianapolis Colts turned around from a 4-12 season in 2017 to 10-6 in 2018, due in large part to the performance of their offensive line. They invested heavily in the trenches during the offseason, adding two through free agency and another two in the draft.
By season's end, Andrew Luck was the least-sacked quarterback in the league, and the line led in sack rate (2.8 percent). Football Outsiders ranked the Colts' offensive line as No. 2 in pass protection and No. 4 in run blocking. Including the playoffs, the offense ran for at least 100 yards in nine games, hitting 150 yards in five games and 200 yards in three of them.
- Started 11-of-11 games (2-of-2 in the playoffs), 744 snaps, two sacks, seven QB hits, 18 QB hurries allowed, four penalties
The Colts started two different players at left tackle for the first five weeks until Castonzo returned to the lineup. A hamstring injury cost him almost the entirety of his summer before a setback in his recovery took the injury into the regular season. The Colts' offensive line really took off when Castonzo got back in, as it averaged just 74.4 rushing yards per game without him and 125.6 with him (including the playoffs). Luck was also sacked 10 times in the first five games compared to 11 in the remaining 13 games.
Pro Football Focus graded Castonzo as the No. 18 tackle in the league.
- Started 16-of-16 games (2-of-2 in the playoffs), 1,136 snaps, two sacks, four QB hits, 17 QB hurries allowed, nine penalties
The rookie phenom was the only Colts offensive lineman to play every snap for the Colts on his way to All-Pro and Pro Bowl honors. Nelson became social media's darling, too, as his weekly pancake blocks were highlighted by various admirers of his play. He was even a candidate for Offensive Rookie of the Year, which just simply doesn't happen for interior offensive linemen. Speaking of things that don't happen for interior linemen, Nelson was the first one to ever be named NFL Offensive Rookie of the Month for his performance in October.
PFF graded Nelson as the No. 6 guard in the league and the No. 1 rookie offensive lineman.
- Started 12-of-12 games (2-of-2 in the playoffs), 777 snaps, one sack, two QB hits, six QB hurries allowed, four penalties
Kelly missed four games in 2018 due to knee and neck injuries, but when he was on the field he was one of the league's top centers. He gave the Colts' offense a huge boost, especially in the run game, as it ran for 116.2 yards per game with him leading the line. Kelly was repeatedly praised for his ability to make calls at the line of scrimmage and keep the other linemen in tune with what to expect.
At one point, former Colts offensive line coach Dave DeGuglielmo called Kelly, "the most complete center" he'd ever coached as well as, "the best center in the National Football League."
PFF graded Kelly as the No. 8 center in the league.
- Started 9-of-11 games (2-of-2 in the playoffs), 601 snaps, one QB hit, 10 QB hurries allowed, six penalties
Glowinski was one of the most pleasant surprises of the Colts' entire 2018 campaign. The team's original plan was for free-agent pickup Matt Slauson to start at right guard with rookie second-round draft pick Braden Smith eventually taking over. Injuries dictated what happened next and Glowinski wound up in the driver's seat at right guard. He did so well that the Colts found their new starting five along the line, and they made sure to re-sign Glowinski shortly after the season so that they can keep that alignment in tact going into 2019.
Like the other linemen, Glowinski fits in well on the Colts line in that he is strong, sets the tone physically and does well on the move.
PFF graded Glowinski as the No. 10 guard in the league.
- Started 13-of-15 games (2-of-2 in the playoffs), 853 snaps, three sacks, six QB hits, 19 QB hurries allowed, three penalties
Nelson, the Colts' first-round pick in 2018, was as good as advertised, and it overshadowed the season that Smith had as the team's starting right tackle. After spending some time at the position during the preseason, Smith got his first full start in Week 5 on national television against the New England Patriots. Just like Glowinski, he would not give the position back. Throughout the season, coaches commented on Smith's strength and his ability to clear a path in the run game.
General manager Chris Ballard recently said the team will give Smith a full offseason of work to continue developing at right tackle.
PFF graded Smith as the No. 25 tackle in the league and the No. 3 rookie offensive lineman.
Starting at right tackle at the time, Haeg landed on Injured Reserve following an ankle injury in Week 3. He would miss the next nine weeks before being activated from IR and returning to the lineup while helping the Colts make their late-season push for the playoffs. He saw 365 snaps on the season and started 6-of-8 games. When not starting, Haeg came in as an extra blocker in heavy packages (big tight end).
The Colts signed Boehm off of the Los Angeles Rams' practice squad in Week 6, and it didn't take long until they needed him in a big way. When Kelly went down with his injuries, Boehm came in to be the team's center, taking over Kelly's responsibilities in making line calls as well. In all, Boehm played 357 snaps and started 4-of-11 games. PFF graded him as the No. 13 center in the league among those that played at least 20 percent of snaps.
Clark saw a good bit of action early in the year when he started the first four games at left tackle before Castonzo returned. Afterward, he also saw snaps in heavy formations as an extra blocker, playing 364 snaps in all and starting 4-of-11 games.
Andrews saw some action late in the season as a fill-in when Boehm briefly went down in Week 13 and Glowinski missed some time in Week 14. Andrews played 36 snaps for the Colts in 2018, being active in three games.
Matt Slauson and J'Marcus Webb
The Colts lost a couple of veteran starters to IR early in the season. Slauson began the season as the team's right guard, starting the first five games before suffering two fractured vertebrae in his back against the Patriots in Week 5. After that, Slauson basically became "Coach Slauson," mentoring the many young players along the Colts' line. He played 376 snaps in 2018.
Webb started Week 1 at right tackle against the Cincinnati Bengals, playing 81 snaps, but then landed on IR with a hamstring injury on the Colts' last offensive play of the game while chasing down a Bengals player who was returning a fumble.
Antonio Garcia, De'Ondre Wesley
The Colts signed Garcia to the practice squad in Week 10, and Wesley from Week 11-12. He was briefly released from the practice squad and then brought back in Week 14. Both players were signed to reserve/future deals following the season.