Kansas City Chiefs running back Jamaal Charles became the second Chief to exit the game against the Cleveland Browns, following Dwayne Bowe, who has a rib injury. Charles' injury isn't totally clear but it appears he might've hurt his ribs.
Charles took a carry down the left side of the field and as he was tackled it looked like he hurt his ribs. Charles grabbed his rib area immediately, apparently in pain. Charles may have fallen on the ball awkwardly when getting tackled.
Charles exited the game while trainers tended to him on the sidelines. The injury came midway through the second quarter.
Charles already has 123 yards in this game, including an 80-yard touchdown run on the first play of the game, so the Chiefs can not afford to lose him.
Update from Adam Teicher:
Charles looking on sideline like he's ready to go back in. Standing and holding his helmet— Adam Teicher (@adamteicher) December 9, 2012
Charles is back in the game.