BREAKDOWN: Despite the fact that there are six different running backs on the roster who have played in a game for the Patriots, the position is very much one of uncertainty heading toward training camp. In fact, many assume/hope the team will add another veteran to the mix at some point this summer. Dion Lewis went from perceived camp body to star in just a couple months last summer. Unfortunately his electric breakout season ended with a torn ACL. While opening camp on PUP remains a possibility, Lewis' appearance at the final OTA session this spring certainly makes it seem likely he'll be ready to open the season on the roster. James White had a pretty nice second season, as the former fourth-round pick filled in for Lewis over the second half of the year to the tune of 40 catches and four touchdowns, including some pretty impressive big plays. Brandon Bolden's versatility, special teams role and team-first work ethic have made him a favorite of the coaches and a virtual veteran lock. The rest, may be up for grabs. LeGarrette Blount re-signed after finishing a somewhat disappointing 2015 season on IR. He was not on the field this spring, but if no other veteran is brought aboard he's still the favorite for the big-back role. The veteran free-agent addition Donald Brown did a lot of work with the passing backs this spring, but the former first-round pick will likely have to open eyes both as a runner and receiver to win a roster spot. James Develin returns from a broken leg as a favorite of the coaching staff (and PFW!). In addition to special teams work he has ability as a blocker from both the backfield and tight end, where he's worked this spring, but when roster cut-downs come fullbacks are always fighting for a spot. Joey Iosefa had one highlight run when he saw game action last fall, but the practice squad 'tweener back just doesn't seem to do anything well enough to warrant a roster spot, while the same could be said for Tyler Gaffney. Both players were cut for a short time this offseason. Finally, D.J. Foster is a versatile playmaker who was both a running back and receiver in college. He spent a lot of time on special teams in spring work, but also missed time to an apparent leg injury. It can't be ruled out that Foster could steal a roster spot, but a slot on the practice squad seems more likely.