UCLA quarterback Patrick Cowan said Saturday he will undergo surgery to repair his anterior crucial ligament in his left knee and will be unable to play in the 2008 season.

Cowan was injured during practice Thursday. Cowan, who will be senior, said he was not sure at this time if he would petition for sixth season of eligibility.

Quarterback Ben Olson, who suffered a broken bone in his right foot Thursday, said he will probably have surgery to place a screw in the foot to help the fifth metatarsal mend. He said he will meet with the doctor on Monday to finalize those plans. Olson said he expects to be out at least six weeks.

Injuries robbed the Bruins of their top two quarterbacks for Saturday’s spring game.