LB Anthony Walker Jr. suffered a knee injury and left Thursday night's game against the Steelers on a cart.
Walker, a team captain, appeared to be stepped on during a second-down play during the third quarter. Players knelt as trainers placed an air cast on his left leg, and Myles Garrett and head coach Kevin Stefanski were among those who went out to console Walker as he left the field.
Jacob Phillips replaced Walker at the middle linebacker position. The Browns trailed the Steelers 14-13 at that point in the game.
LB Jeremiah Owusu-Koramoah (quadriceps) and DT Taven Bryan (hamstring) were also ruled questionable with injuries in the third quarter. S Ronnie Harrison Jr. (hamstring) was injured during pregame and was ruled out.