Midway through the third quarter with the Browns trailing 13-3, quarterback Jason Campbell took a blindside hit from Steelers cornerback William Gay, lost the ball as he went to the ground, and remained there as the Steelers Will Allen returned it to the Browns' four-yard line.
Campbell laid on the ground for several minutes before making his way to the bench. A short time later, he was taken to the locker room in a cart where he was evaluated for a head injury.
A play after the fumble, Ben Roethlisberger found Emmanuel Sanders for a touchdown, and Pittsburgh led 20-3.
Campbell, who left for one play in the second quarter after re-aggravating a rib injury, was replaced by Brandon Weeden, the Browns' 2012 first-round pick, lost his job earlier this year to Campbell.
