On the Bears' second possession of the game, Knox caught a 17-yard pass over the middle of the field. Knox then lost control of the football and a scramble for the ball followed.
Seattle defensive lineman Anthony Hargrove came flying in and hit Knox up high. The wide receiver's head snapped back due to the force of the hit.
Knox was seen moving his hands as he was taken off the field on a stretcher. The Bears ruled Knox out for the rest of the game with a back injury.