Dickerson had 2105 yards in 1984.
When talking about the rushing record, it should be noted that OJ Simpson ran for 2003 yards in 1973 in a 14 game season and Jim Brown ran for 1863 yards in 1963 in a 12 game season. Dickerson got his record over a full 16 game season, yet no one mentions that both Simpson and Brown would likely have passed that number over 16 games. (Then again, OJ got away with a double murder, so I guess he's got nothing to complain about)
Could Ricky pass up 2105? My guess is no. More to the point, I'd say, "he'd better not." The amount of workload that Ricky would need to run for over 2105 yards would be a career killer. Three straight years around 400 carries would have us looking for a new starting RB by 2006. He'd almost certainly break the NFL record for carries, 410 (I think), if he was to break the single-season rushing record.