Pittsburgh Steelers quarterback Ben Roethlisberger has a hyperextended left knee and a bone bruise sustained during a game-winning field goal drive at the end of a 24-22 victory at San Diego on Monday night, but hasn't been ruled out of Sunday's game against Jacksonville. The injury isn't as severe as it initially appeared to be -- immediately after the game, coach Bill Cowher said "it looked bad." "It's a deep sigh of relief," Cowher said Tuesday. Roethlisberger, 16-1 as an NFL regular-season starter, was injured with 1:05 remaining when Chargers defensive end Luis Castillo's helmet collided with his left knee as Roethlisberger was completing a 9-yard pass to Antwaan Randle El.