Boulder, Colo. ? Colorado senior cornerback Lovell Houston could be facing his fifth shoulder surgery and possibly the end of his football career.

Houston, whose right arm has been in a sling the last few days, has an unstable shoulder, said Colorado Buffaloes head trainer Steve Willard. He said surgery may not be imminent, but Houston is headed in that direction.

Houston has had reconstructive surgeries on both shoulders in the past. He has played in one game this season, against San Diego State, in which he recorded four tackles and a fumble recovery.

Houston’s younger brother, Marcus, is continuing to rehab his right knee. The sophomore running back won’t play Saturday against Kansas University.