Free-agent fit: Running backs

Third in a multi-part series on free-agent fits at various positions leading into the start of free agency March 13.

Position: Running back

Players under contract for 2012: Eric Kettani (RB/FB), Lousaka Polite (FB), Stevan Ridley, Shane Vereen, Danny Woodhead

Level of need: Moderate

Projected top targets: Michael Bush (Raiders), BenJarvus Green-Ellis (Patriots), Mike Tolbert (Chargers)

Why Bush fits: At 6-foot-1 and 245 pounds, he is a bigger back who could help the Patriots return to more of a 2004-style of attack that featured a lot of banging from Corey Dillon. He enters his fifth season and also has shown the ability to be a factor as a pass-catcher.

Why Green-Ellis fits: He knows the offense, is dependable, and is a hammer on the goal-line. Not to mention, he contributes on special teams. The 26-year-old is entering his prime years.

Why Tolbert fits: At 5-foot-9, 243 pounds, he falls into the bigger back category and could be a nice complement to those already on the roster in Ridley, Vereen and Woodhead. He enters his fifth season.

Other names of note: Cedric Benson (Bengals), Ronnie Brown (Eagles), Ryan Grant (Packers), Tim Hightower (Redskins), Peyton Hillis (Browns), Mewelde Moore (Steelers), Derrick Ward (Texans)

Market conditions: Top backs like Matt Forte and Ray Rice were assigned the franchise tag, making two of the league's top backs essentially off limits. And Marshawn Lynch signed an extension with Seattle. So that has watered down the market, as expected. More complementary parts here instead of workhorses.

Questions to answer at position: How far would the team financially extend to keep Green-Ellis? ... Are Ridley (3rd round, 2011) and Vereen (2nd round, 2011) ready to take the next step? ... Is it time to develop a pure fullback and have that position make a return to the offense?

YOUR TURN: Which of these would you like to see in a Patriots uniform? Share your thoughts in the comments section of this blog entry.