Over the last half of a decade, so much has been made about the Kansas City Chiefs' incredible offense, led by Patrick Mahomes, Travis Kelce and Andy Reid. But something that has gone under-appreciated about the Chiefs on that side of the ball, particularly this year, is how rock-solid their offensive line has been.

It would be an easy case to make that Joe Thuney, Trey Smith, and Creed Humphrey make up the best interior of any offensive line in the NFL. The problem for the Chiefs, as they head into Super Bowl 58 — their fourth Super Bowl appearance in the last six years — is that they will be playing without left guard Joe Thuney, according to NFL Network's Ian Rapoport.

Thuney, a three-time All-Pro guard and undoubtedly one of the best players on the entire roster, suffered a pectoral injury during the Chiefs' Divisional Round win over the Buffalo Bills. The injury was severe enough that it kept him out of Kansas City's AFC Championship Game win in Baltimore.

with Joe Thuney out, Chiefs must lean on ‘Mr. Reliable' one more time

Chiefs guard Joe Thuney

In Thuney's place, it was fifth-year backup Nick Allegretti who stepped in, holding up just fine in the win over Baltimore, giving up just one sack and three hurries on 52 pass blocking snaps, per Pro Football Focus. Now, with a Super Bowl date with the 49ers set for this Sunday, the Chiefs are once again turning to Allegretti.

This bad news was expected. “I would probably bet towards Allegretti playing,” Andy Reid told pool reporter Peter King on Thursday, per a tweet from ESPN's Adam Schefter. “For Joe, it’s a strength thing. Right now, it’s not strong enough.”

While it's certainly a major blow for the Chiefs to have to play the two most important games of their season without one of the best left guard's in all of football, the Chiefs have rallied around Nick Allegretti, a former seventh-round pick who Travis Kelce recently referred to as “Mr. Reliable.”

“Nick has been year in, year out Mr. Reliable every single time he gets the opportunity to go in there,” Kelce said during a recent episode of his ‘New Heights' podcast (h/t Kyle Tausk of SB Nation). “To play as good as he did and to play as big as he did in that moment, in that game, we couldn’t have did it without you brother.”

Once again, Allegretti will have his hands full against the 49ers. Even though San Francisco is just 30th in the NFL in blitz rate, Javon Hargrave and Arik Armstead have been two of the most impactful interior pass rushers in the NFL this season. How Allegretti holds up is just one of many developments to keep an eye on during Super Bowl 58.