Steelers star T.J. Watt went down with an ankle injury late on Sunday afternoon in Pittsburgh’s 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 the Steelers’ sideline on his own and he immediately went to be checked out by the team’s medical staff.

Watt reportedly threw his gloves to the ground and walked 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 this season, his eighth with the team.

Steelers head coach Mike Tomlin said after the game that Watt went down with a low ankle injury, which Watt later confirmed.

Further specifics are not yet known, and he’s set to undergo further testing in the near future. 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 the Steelers on the ground with just 14 yards on six carries, and Calvin Austin III had 65 yards on five catches.

Hurts went 25 of 32 for 290 yards with two touchdown passes, 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 Philly’s 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. Despite the loss, they still clinched a playoff berth for the fourth time in the last five seasons.