Cowan underwent two sets of X-rays which revealed a small pneumothorax - or collapse - of his right lung. However, the junior is in stable condition and was released from the University of Arizona hospital early Sunday morning.

Cowan suffered a concussion in the third quarter of Saturday's 34-27 loss to Arizona. After leaving the game just before the second series of the quarter, he began feeling shortness of breath in the locker room and was taken by ambulance to the hospital.

The collapsed lung marks the latest - and certainly the most serious - in a long line of injuries this season for Cowan, who had been playing with a torn ligament in his right knee.

The 6-5 Cowan has appeared in four games this season for the Bruins (5-4), completing 53 percent of his passes for 540 yards, three touchdowns and one interception.