Colorado will keep its starting quarterback a mystery as it travels to Houston to play the Big 12 opener for both teams on Friday night.Buffaloes coach Deion Sanders denied reports that Ryan Staub would start the game.The Buffaloes (1-1) used a three-quarterback rotation in a 31-7 home win against Delaware last Saturday, but it was Staub who served as catalyst for the Colorado passing attack.The sophomore was the third Buffaloes’ signal-caller and connected on 7 of 10 passes for 157 yards and two touchdowns.”I’m not confirming nothing to y’all,” said Sanders, who added he wants to commit to a full-time starter. “We ain’t like that. We are good. We have capable guys. Staub has done a phenomenal job and got the majority of the reps. But I haven’t made that assessment or that decision yet (on a starter).”While which quarterback the Cougars (2-0) will face remains uncertain, coach Willie Fritz noted his defense, which is ranked No. 4 nationally, will prepare for the Colorado system in general.