Pittsburgh Steelers rookie linebacker Sean Spence has been carted off with what looks like a serious left leg or knee injury late in the third quarter of the preseason game against the Carolina Panthers.

Spence stayed on the ground in pain after his leg caught in the torn up turf of Heinz Field. The team doctors put an air cast on his leg prior to him being carted off. The injury did not look good on replay.

Spence was attempting to chase Panthers quarterback Jimmy Clausen, who had just left the pocket to his right, when he suffered the injury.

Head coach Mike Tomlin will update the status of Spence after the game, but do not expect good news.

Below is a screen shot from the video replay.