Texas will be without its starting quarterback for the second time in three games.
David Ash will not travel to Texas' game against Iowa State on Thursday, the school announced on Wednesday afternoon. Case McCoy will start for Texas.
Ash suffered a concussion in a loss to BYU and missed the following game against Ole Miss. He returned against Kansas State, but suffered more symptoms of a head injury and missed the second half of the 31-21 win.
McCoy was 5-of-9 for 59 yards after replacing Ash against K-State. He completed 24-of-36 passes for 196 yards and a touchdown. He also rushed five times for 14 yards.
Texas could play freshman Tyrone Swoopes, who turned heads with a strong performance in the spring game, but has yet to appear in a game this season, preserving a possible redshirt season.
Brown noted this week that the coaching staff had prepared Swoopes to play for the last three weeks and there was a plan to get him playing time alongside McCoy, if necessary.