Ash took several hard hits in a 38-7 win over North Texas. Longhorns coach Charlie Strong says Ash didn't show any symptoms during the game, but that the coaching staff got a call later that night.
Strong did not detail what problems Ash was experiencing.
Ash ran for a touchdown and passed for another. But he also took several blows to the head, including a tackle when he bent low to pick up a fumble, and twice more when his helmet bounced off the turf.
Sophomore Tyrone Swoopes will start for Texas (1-0) against the Cougars (1-0).