OK, here's my theory... feel free to poke holes in it.
Against the stronger teams (MSU, OSU and Wisky), the coaches knew that Iowa was not going to be able to control the LOS and that the RB was going to get hit in the backfield a lot. They needed a back that can get past the first hit, at least some times. In the past, Canzeri seemed to go down pretty easily on first contact; at least some times Wiseman can get a few yards after contact.
Today, the coaches were confident that Iowa would control the LOS so they wanted the back with the best potential to break off a long run.
Against the stronger teams (MSU, OSU and Wisky), the coaches knew that Iowa was not going to be able to control the LOS and that the RB was going to get hit in the backfield a lot. They needed a back that can get past the first hit, at least some times. In the past, Canzeri seemed to go down pretty easily on first contact; at least some times Wiseman can get a few yards after contact.
Today, the coaches were confident that Iowa would control the LOS so they wanted the back with the best potential to break off a long run.