Iowa State quarterback Austen Arnaud returned after a two-game absence, but had to be taken out of the game late in the second quarter after re-injuring his right hand.
Redshirt freshman Jerome Tiller replaced Arnaud with 3:57 to play before halftime in the middle of a series.
Arnaud was 6 of 11 passing for 48 yards and an interception. He ran five times for 5 yards.
There is no word on his return to the game. He was throwing passes before the start of the second half, however.
ISU trails No. 18 Oklahoma State 13-0 at halftime.
Tiller started the last two weeks at Nebraska and Texas A&M. The Cyclones scored only two touchdowns in those games.