Oklahoma State had a serious injury to their starting quarterback on Friday night in their matchup against BYU. Shortly before the end of the second quarter, Cowboys’ quarterback Garret Rangel was walking very gingerly as he headed to the locker room with trainers. Here is the update from Paul Carcaterra of ESPN. “Garret Rangel in a lot of pain. I was walking towards the tunnel where Oklahoma State’s locker room is and trainers were having to hold that left arm to support the shoulder, it seemed. He was walking very gingerly. Not good for Oklahoma State. I’ll talk to Mike Gundy at halftime and…