Lions beat writer Anthony Kuehn on the team's running back committee...
It is presumed that Reggie Bush will be 1A and Joique Bell 1B like last year, but I believe Bell has a good chance of edging into that 1A slot. Bell is a more decisive runner, hitting the hole hard rather than dancing, and he’s harder to tackle. I think defenses will be more likely to put an eighth man in the box against him than against Bush.
Bush still would have a big role in the offense, but he could be a bigger threat going back to his jack-of-all-trades role, which would lessen his workload and keep him fresh all season. He definitely looked worn down by the end of last season and broke fewer big plays.
The Lions hired Joe Lombardi (formerly of the Saints) to run the offense. The general consensus is that he’s going to run the ball more, but the Saints actually threw it more often than the Lions did in 2013 (from a pass/run standpoint). However, with the way team personnel are talking about the new offense, we’re relatively certain that he’s going to utilize Reggie Bush in more of a receiving role. Bush saw about 50% of the carries in 2013, while Bell’s number was called 37% of the time. Lombardi was in New Orleans during Bush’s stint there, so he was around while Bush’s average carries dropped from 13.1 in 2007 to a career low 4.5 in 2010, his final season with the Saints. Bush has had far more success running the ball after leaving New Orleans, averaging 4.6 YPC with the Dolphins and the Lions compared to his 4.0 YPC while with the Saints. So while Bush probably won’t be ignored in the running game, the split could easily flip to Bell in a lead rushing role. Bell finished with 219 touches in 2013 (finishing as the #17 RB in standard formats) and the team just extended his contract, indicating that he’s a big part of their long-term offensive plan. He’s going in the #22-#25 range, but has upside from there as a potential 240-touch running back in a good offense.