PULLMAN, Wash. -- Washington State quarterback Jason Gesser left Saturday's game against Montana State after injuring his ribs and right shoulder.

Gesser, who throws with his right arm, went to the locker room after being sacked while throwing with about 11 minutes remaining in the third quarter, and the 16th-ranked Cougars leading 31-7.

Backup Matt Kegel entered the game and led a 75-yard scoring drive.

The Pacific-10's leading passer last season, Gesser threw for 3,000 yards and 25 TDs in a 10-2 season, one of the best ever for Washington State.

Gesser, who threw five touchdowns in his first three games this season, entered Saturday's game averaging 236 yards.

The 6-foot-1, 207-pounder from Honolulu played in last year's Sun Bowl with a broken right hand and missed the final two games of his sophomore season with a broken left leg.