Colbert, a junior from Shawnee Mission, Kansas, started all 13 games last season at outside linebacker, recording 61 tackles, including 2.5 tackles for loss, one interception and four pass breakups. He played with a torn labrum during the season and underwent surgery in January. McCall, a redshirt freshman from Pensacola, Florida, did not appear in any game action last season.
Colbert and McCall will remain on scholarship and will not lose a year of eligibility. Iowa is scheduled to open the season Oct. 24 at Purdue.