Iowa is absolutely a pre-season Top 25 team. They lose Shonn Green, the two defensive tackles (King and Kroul), and a couple of very replaceable O-linemen. In fact, they replace their guard with an all-Big Ten tackle from two seasons ago who missed last year due to injury (Dace Richardson). And, they replace the center with former Cretin standout Rafael Eubanks, who started at center two and three seasons ago there, and they have some other guys in the mix there, too. Bulaga and Calloway are bookend future NFL tackles for them. If the new D-linemen step up, they could easily contend for a share of the Big Ten title. They have a tough schedule with road games at OSU, PSU, MSU, and Wis. If they split those four (possible), and sweep at Kinnick (possible), then 6-2 could get them a share of the Big Ten title.
In reality, Iowa has fewer question marks than Michigan State, Wisconsin, Illinois, and Michigan. If there's a third Big Ten team in the Top 25, it should be them. Minnesota returns a lot, but we failed down the stretch last year while the Hawkeyes rolled. That keeps us off of anyone's radar.