"Aaron's battled significant injury problems since the spring and at this time feels he needs a break from football. We are very appreciative of Aaron's many contributions - he's been a valued team member and I am hopeful he may decide to return at some point in the near future."
Greving was injured prior to Iowa's season opener and has played in only five games. He has rushed 39 times for 120 yards. He entered fall drills listed as the No. 1 running back, but an ankle injury has hampered Greving most of the season. He has 453 career rushing yards on 99 carries.