One of the key cogs in the Titans’ backfield is reportedly on the mend. Tailback Shonn Greene “recently” had right knee surgery, Jim Wyatt of the Nashville Tennessean reported on Sunday. It is the second surgical procedure on Greene’s knee since the start of the 2013 regular season. According to Wyatt, it is anticipated Greene will return for the start of training camp, but he will miss the club’s remaining offseason workouts for Tennessee, which released starting tailback Chris Johnson earlier in the offseason. Greene, 28, rushed for 295 yards and four touchdowns on 77 carries in 2013. The 5-11, 233-pound Greene is the Titans’ top veteran option at tailback, with rookie Bishop Sankey also likely to have a regular role in the backfield. A second-round pick from Washington, Sankey (5-9, 209) was the only back the Titans selected in the draft.