EARTH CITY, Mo. -- The St. Louis Rams don't start organized team activities until June 3, but with most of the offseason heavy lifting complete, the current roster likely will make up the vast majority of players come the start of the regular season.

With that in mind, we'll spend the next week or so delving into each position group with some thoughts on who will start, who might be on the bubble and how the depth chart could shake out.

Position: RB

Returning: Tre Mason, Benny Cunningham, Chase Reynolds, Trey Watts, Isaiah Pead

Newcomers: Todd Gurley, Malcolm Brown, Terrence Franks, Zach Laskey

Departures: Zac Stacy

Projected starter: Mason (until Gurley is healthy)

Battle to watch: There's an argument to be made here that the battle to watch is for the starting job between Mason and Gurley. At this point, we don't know when Gurley will be healthy but when he does return, it's pretty safe to assume he'll be the starter. Coach Jeff Fisher has already referred to Gurley as the team's "back of the future" and acknowledged that he envisions Gurley becoming his new Eddie George. So the attention here turns to how the Rams plan to sort things out beyond the top three of Gurley, Mason and Cunningham, who figures to stick because of his ability to help on special teams and in pass protection. The Rams have kept five running backs the past two seasons with Reynolds and Watts contributing on special teams last year. Now, there figures to be a four-way battle for the remaining two spots with Reynolds, Watts, Pead and Brown as the contestants. Brown was one of the more coveted rookie free agents for the Rams and could push Watts for a spot if he can prove valuable on special teams. Pead seems to be on his last chance and will also need to prove capable of helping on special teams. Reynolds is a core special teams player and will be hard to displace on the roster.

Outlook: In this edition of the Rams offense, there's no more important position than running back. Gurley clearly comes with the most talent and could have a big future but it remains to be seen when that future will begin. His time will come but it might not be for a few weeks which means it's on Mason to carry the load in the meantime. Mason rushed for 765 yards while averaging 4.3 yards per carry as a rookie but the Rams would like to see more consistency from him on a carry-to-carry basis. Ideally, Mason's home run ability will complement Gurley's every down running with Cunningham helping out on third downs and in clear passing situations. The Rams have made no bones about what they want to be offensively and the amount of talent to have more success on the ground looks to be in place. Until Gurley returns and proves himself, though, the rest of the group will need to pick up the slack.