Chiefs vs. Steelers Grades: How is Joe Thuney Performing at Left Tackle?

After three games with Joe Thuney at left tackle and Mike Caliendo at left guard, how has the Chiefs' offensive line performed to close out the regular season?

Sep 22, 2024; Atlanta, Georgia, USA; Kansas City Chiefs guard Joe Thuney (62) celebrates after a victory over the Atlanta Falcons at Mercedes-Benz Stadium. Mandatory Credit: Brett Davis-Imagn Images / Brett Davis-Imagn Images

The Kansas City Chiefs battled issues at the left tackle position throughout much of 2024. With the regular season now all but officially over for KC, do they know who will protect quarterback Patrick Mahomes's blindside throughout the playoffs?

While the offensive line appeared to stabilize with left guard Joe Thuney's move to left tackle (and backup lineman Mike Caliendo's move to the starting left guard position), the Chiefs' Pro Football Focus grades from their Christmas Day win over the Pittsburgh Steelers suggests that there may be more than meets the eye as Kansas City prepares to make a run at the NFL's first three-peat.

On Wednesday, Thuney earned a 58.1 grade from PFF, his second-worst overall grade of the season. His worst mark came in his first start at left tackle in Week 15 against the Cleveland Browns. While Thuney's 68.3 grade against the Houston Texans was closer to his usual standard, PFF's grades have painted a clear picture: Thuney is an elite guard and a helpful (but not great) left tackle.

Those marks are no insult to Thuney, and they reflect the Chiefs' own moves throughout the year. Thuney was a "break glass in case of emergency" tackle choice for Kansas City. After a disastrous start to Kingsley Suamataia's career, KC went to Wanya Morris. As Morris struggled later in the year, the Chiefs signed D.J. Humphries. After Humphries was injured, Thuney got the call. This wasn't the path the Chiefs wanted to take; their hand was forced by a series of unfortunate events.

Meanwhile, as noted by Shaun Newkirk on Twitter/X, Caliendo has been PFF's lowest-graded left guard and second-lowest-graded guard across the NFL in the last three weeks. Newkirk also accumulated Thuney's stats and grades from the last three games, resulting in a 58.3 overall grade, 53.1 run block grade and 58.2 pass block grade, allowing 14 pressures on 128 "real pass snaps," per PFF's metrics.

Had a question about how the Chiefs O-line could grade so poorly despite PIT only having 5 pressures:

1) run blocking was pretty bad
2) Grades are adjusted ultimately for things like time to throw and true pass sets
3) Taylor had a ton of penalties (which matter!) https://t.co/nRKd0wpjkl pic.twitter.com/a3XovGpXBN

— Shaun Newkirk (@Shauncore) December 26, 2024

In a film review in The Chief in the North Newsletter, Seth Keysor charted Thuney and Caliendo's snaps from the Chiefs' win over the Texans and later added that the duo's performance against the Steelers did not change his view of KC's situation. In Keysor's evaluation, Thuney was "OK" at left tackle against Houston, "but not great or even good, with a particular weakness to power rushes." He also noted the disparity between Thuney and Caliendo's performances at guard.

Evaluating how Thuney's situation differed from some of the Chiefs' earlier efforts to steady the left tackle position, Keysor added that Thuney "had plenty of reps in which he was given assistance either via direct help (a tight end chip or Caliendo coming over to help inside, which allowed Thuney to set up outside), or through schematic help (rollouts the other direction, slides, screens, quick throws etc.)," often in ways head coach Andy Reid did not do as frequently for Suamataia or Morris.

Ultimately, after an appropriate hat-tip to Thuney's efforts in an exhausting stretch of three games in 11 days, the Chiefs appear poised to see if Humphries can suit up and play alongside many of KC's backups in Week 18 against the Denver Broncos. If Humphries can stay healthy and show that he's ready for a playoff run, the Humphries-Thuney tackle-guard duo may still be the Chiefs' best option.

Read More: Chiefs vs. Steelers Snap Counts: Season-Long Streak Ends, Defensive Backs Continue Rotating