Jaguars pass rusher Josh Allen was injured in the third quarter.
Allen remained down after Ben Roethlisberger completed a 4-yard pass to JuJu Smith-Schuster with 8:52 remaining in the third quarter.
He was helped off the field and, after an examination in the blue medical tent, was escorted to the locker room.
Allen has a knee injury, and the Jaguars downgraded him to out after initially listing him as doubtful.
Allen had no stats before leaving.
He entered the game with 13 tackles and 2.5 sacks in seven games.
The third quarter was otherwise uneventful as the Steelers maintain their 17-3 lead at the start of the fourth quarter.