Iowa is replacing a lot of production this year along the defensive line, and that is going to be something to watch during fall camp. During Big Ten Media Days, Kirk Ferentz alluded to using more depth and put some pressure on this unit to grow during fall camp. Iowa's Defensive Line StartersRight now, Iowa has a handful of talents that expect to be eating the bulk of the snaps on the defensive line. In the Big Ten, you need more than five guys up front, though, and Kirk Ferentz expects Iowa to stay fresh with rotations. Phil Parker's defense is predicated on the defensive line owning its gap responsibility, which is what the rotation will demand.