In a must-win game for the Pittsburgh Steelers, their star linebacker suffered an injury that took him out of the game.

Pittsburgh’s T.J. Watt suffered a knee injury in the second half on Saturday in a 17-10 win over the Ravens, and after being examined in the blue medical tent and heading to the locker room, he was ruled out for the remainder of the game.

In the third quarter, Baltimore quarterback Tyler Huntley rolled out for a pass to his right that was batted down by Steelers tackle Montravius Adams.

But as Adams knocked the ball down, his momentum carried his off toward Watt, knocking into the linebacker in what appeared to be his left knee.

Watt lay on the ground and was eventually helped out by the training staff, walking to the locker room under his own power.

According to NFL Media’s Ian Rapoport, initial tests indicate Watt suffered a grade 3 MCL sprain, which would be considered a multi-week injury.

He will still undergo further testing.

Per ESPN’s Adam Schefter, Watt wanted to come back into the game, but the Steelers did not allow it.

Before the injury, Watt put up gaudy numbers in the game, recording eight tackles and two sacks as the Steelers hope to earn a spot in the postseason.

Watt will finish the regular season with 19 sacks, 68 tackles and one interception.

He was named to the Pro Bowl earlier in the week.