Pittsburgh Steelers star T.J. Watt went down with an apparent foot injury late on Sunday afternoon in their 27-13 loss to the Philadelphia Eagles.

Watt, while trying to get to Eagles quarterback Jalen Hurts in the fourth quarter at Lincoln Financial Field, suddenly started hopping and favoring his left foot. Watt didn’t seem to do anything specifically before he popped up, but he was clearly in a lot of pain and fell to the ground after a few steps.

Watt eventually made it to their sidelines on his own, but he immediately went to be checked out by the team’s medical staff.

Watt was then seen throwing his gloves to the ground and walking to the locker room after leaving the medical tent. He did not return to the game. Watt has 40 total tackles and 11.5 sacks so far this season, his eighth with the team.

Further specifics of Watt’s injury are not yet known. The Steelers were down by 14 points when Watt went down, and the game was out of reach. Russell Wilson went 14-of-22 for 128 yards and a touchdown for Pittsburgh, which dropped to 10-4 with the loss. Najee Harris led them on the ground with just 14 yards on six carries, and Calvin Austin had 65 yards on five catches.

Hurts went 25-of-32 for 290 yards with two touchdowns, and he ran in a third in the win for the Eagles. They now sit at 12-2 and have won 10 straight. A.J. Brown, who went down with an injury of his own later in their final drive, had a game-high 110 yards and a touchdown on eight catches.

The Steelers, who still hold the lead in the AFC North, will take on the Baltimore Ravens next weekend.