Iowa freshmen Barkley Hill and Ruben Lile will redshirt the 2012 season because of injuries.
Hawkeyes coach Kirk Ferentz says Hill, a running back, tore the ACL in his left knee during practice on Saturday and will have surgery later this week.
Hill was in the mix for playing time as a true freshman because of Iowa's lack of depth at back. But his absence for the upcoming season means that Damon Bullock and freshman Greg Garmon will likely occupy the top of the depth chart.
Ferentz says that Lile, a freshman defensive back from Detroit, suffered a similar injury to Hill's without getting into further details.
The Hawkeyes open the season on Sept. 1 against Northern Illinois in Chicago