The Lions have upgraded their depth to the point where they'll have some interesting position battles come training camp. Either George Foster or Jonathan Scott could be out of a job at tackle. There may not room for all of the veterans vying for time at linebacker (much will depend on the progression of rookies Jordon Dizon and Caleb Campbell). And currently there's a logjam at running back.

With a mandatory minicamp and 11 OTAs to go, there's plenty of time to set a pecking order in the backfield. Still, it was interesting to hear coaches this week praise Brian Calhoun's running ability and admit Tatum Bell was a tad overweight. Rookie third-round pick Kevin Smith is going to make the team and eventually become a starter. He's a special-teams demon, too. Beyond that, it's anyone's guess how the depth chart plays out.

Bell has had the most success (1,025 yards two seasons ago in Denver) and is the Lions' best option at running back if Smith can't win the starting job out of camp. Only problem is he's not much of a special-teams player (at least the Lions never tried him there last year when he was demoted to third string) and Lions coach Rod Marinelli values that in his reserves. Calhoun was a productive runner in college, but he's not an every-down back in the NFL. He does add a dimension as a pass catcher and Marinelli said this week he can cover on returns. Still, I'd be worried since his last two seasons were cut short by knee injuries.

If Calhoun proves he can be more than a third-down back, Bell's days could be numbered (especially if he shows up for camp overweight). If not, Calhoun, Aveion Cason and Artose Pinner would seem to be competing for probably two spots. Both Calhoun and Cason can return kicks, while Cason and Pinner are best suited for downfield coverage. Pinner doubles as a tough inside runner, but rookie fifth-round pick Jerome Felton could easily fill that void. Felton should make the team as one of two fullbacks, probably with Jon Bradley, though Sean McHugh's versatility at tight end could be a factor.

Bottom line, the Lions have a number of options at running back and they have until late August to sort them out.