Oakland quarterback Jason Campbell was knocked out of the Raiders' exhibition game against the San Francisco 49ers on Saturday night with a possible concussion after getting kneed in the helmet. Campbell was hurt while scrambling on a play late in the second quarter. He lost the ball on the play and then got hit by defensive lineman Justin Smith and linebacker Ahmad Brooks as he fell to the ground to recover his own fumble. Read more: http://espn.go.com/nfl/story/_/id/6...-jason-campbell-leaves-preseason-game-injured
