I don't know if this information has been stated before and as I read this (http://www.annarbor.com/sports/um-football/rich-rodriguezs-lone-win-against-penn-state-one-to-remember-plus-michigan-football-injury-report/) mgo.licio.us article I noticed an interesting point on Mike Cox by RR. "Rodriguez disclosed Wednesday that running back Michael Cox has had “a knee issue” for the past few weeks, and that his growth and practice has been limited." This could be why we haven't seen much of him and why Hopkins has emerged as the big back. I for one have been more than happy with Hopkins and I think we will see a lot of him this coming week against Penn State.
Hoke was top notch at this aspect of his job.