Not knocking on him, but when did Jewell "bail us out" in 2008? IIRC, the running game kind of stalled after Greene left the Northwestern game. The Indiana game in which Hampton scored 3 TD's was pretty well over when Greene was pulled out. Jewell was the perfect guy to have give Greene some breathers, but Greene was still a true workhorse.
Other examples from last season (not all are returning): C.J. Spiller (this past season he pretty much carried the load), Daniel Thomas at K-State, Kendall Hunter at Okie State, Jacquizz Rodgers at Oregon State, Toby Gerhart, Ryan Williams at Virginia Tech, and Clay. Now not all of these guys are going to be 100% every week, but I really don't think there's ever been a running back that was 100% week in, week out. That just defies the nature of the position. Some are tougher than others, and will play trough the pain. But none of them just stay 100% healthy for every game.