The 2017 season manages to get worse for the Denver Broncos.

Buried in the mess that was their 21-14 loss to the Oakland Raiders on Sunday, the Denver Broncos lost Domata Peko, the Broncos’ best interior defensive lineman in 2017, to a knee injury late in the third quarter, which resulted in him being carted off the field.

Head coach Vance Joseph said postgame that Peko will undergo an MRI on Monday when the team is back in Denver.

Having already lost Derek Wolfe in the first quarter to a neck injury, the Broncos were without their best two run defenders late in the game.

Even for the portion of the game that Peko was healthy, the Raiders did their best to exploit the weakened interior defensive line with their run game. The Raiders finished the game with 104 yards on the ground. Peko left the game with six total tackles. While you can live with those numbers, it’s fair to assume that they’ll only get worse if Peko misses significant time.

Missing time is something that Peko is unfamiliar with. Just two weeks earlier, Peko extended his starting streak to 118 games, the longest active starting streak for a defensive lineman. Sunday’s game marked the 120th game that Peko started.

Peko has turned out to be one of the Broncos’ most valuable offseason additions. Prior to Sunday’s loss, the 11-year defensive lineman had already accumulated 29 total tackles on the season, the ninth highest number on the team and the first among any Broncos defensive linemen.

Peko entered the game with 23 combined tackles. His six tackles Sunday were second-most on the season behind a seven-tackle effort in the loss to the Giants that started Denver’s current losing streak. Sunday’s loss marked their seventh straight, their longest since 1967.

It’s hard to imagine a season getting much worse for the Broncos. Losing Peko would just be another addition to the long list of things that have gone wrong in this historically bad season.