Iowa State coach Paul Rhoads says backup safety Earl Brooks is out for the season after tearing the anterior cruciate ligament in his left knee.
Brooks, who played in all 12 games last season as a reserve, entered fall camp as the backup to Ter'Ran Benton.
Iowa State also released its latest depth chart Thursday, which offered few surprises from the one the Cyclones opened camp with earlier this month.
One of the biggest changes is that freshman C.J. Morgan and sophomore Deon Broomfield are listed as co-starters at linebacker. Morgan and Broomfield had been listed as safeties, an indication that the Cyclones are stacking their defense to combat the pass-happy attacks prevalent in the Big 12.
Iowa State hosts Northern Iowa in its opener on Sept. 3.