The retirement of Ricky Williams leaves the Ravens with one running back who has more than five career NFL carries -- and that's Ray Rice, who is an unrestricted free agent this offseason.Here's a quick look at who the Ravens have on the roster (besides Rice) and a little speculation with three free-agent running backs and three soon-to-be draftees who might fit with the team.On the roster:Anthony Allen, 2nd season: A seventh-round draft pick in 2011, Allen beat out Jalen Parmele last summer to be the No. 3 back. A downhill runner, he rushed for eight yards on three carries.Damien Berry, 2nd season: As an undrafted free agent, Berry was on the team's practice squad in 2011. He showed good quickness and vision in college at Miami and is an intriguing prospect.Matt Lawrence, 4th season: For a second straight year, he spent the season on injured reserve. Lawrence, a restricted free agent, hasn't made an impact since receiving four carries in 2009.On the market:Cedric Benson, 8th season: Replacing one former Longhorns back with another? With his physical, one-cut running style, the 29-year-old has had three consecutive 1,000-yard seasons.Ryan Grant, 6th season: Grant, who had a pair of 1,200-yard rushing seasons with the Green Bay Packers, can do a little bit of everything, including subbing in on passing downs if needed.LaDainian Tomlinson, 12th season (???): Tomlinson, one of the most productive backs in NFL history, could also retire. But if L.T. wants one more shot at a ring, he would be a great fit here.In the draft:Dan Herron, Ohio State: One of the Buckeyes involved in the tattoo scandal, Herron is short but stout and is more of a straight-ahead runner. He scored 33 touchdowns in his collegiate career.Isaiah Pead, Cincinnati: This 5-foot-10 sparkplug is on the rise after being named the 2012 Senior Bowl MVP. He also showed promise as a dangerous returner, something the Ravens lack.Bernard Pierce, Temple: He can play the physical, change-of-pace role that Williams and Willis McGahee played in recent seasons. He is projected to be a second-day pick in April's NFL draft.