FOXBOROUGH, Mass. -- The New England Patriots have four pure running backs on their roster, which is light compared to the rest of the NFL. The Pittsburgh Steelers, for example, have seven running backs.

So that is an obvious position for the team to bolster between now and the end of the month, when all teams will fill out their 90-man rosters.

Last year, the Patriots had eight pure running backs on their 90-man roster.

The current running back personnel: James White, Dion Lewis, Rex Burkhead and D.J. Foster.

With multiple spots to fill, the club took a closer look at veteran Adrian Peterson on Monday, although Peterson left town without a deal. LeGarrette Blount also remains a free agent, and until he signs elsewhere, there's a possibility he could return.

I'm also told that the door hasn't been closed on Brandon Bolden returning.

One of the team's unrestricted free agents, the 5-foot-11, 220-pound Bolden has primarily been a core special teams player in his five seasons in New England. When the Patriots reached agreement with Burkhead, the former Cincinnati Bengals running back, on a one-year contract with a maximum value of $3.15 million, it would have been easy to assume that Bolden wouldn't be back. Burkhead, like Bolden, is a solid special teamer.

But the Patriots and Bolden have maintained an open dialogue, and with no other suitor stepping up to sign Bolden, it wouldn't be a surprise if he's back in New England when all is said and done.