Debatable. He would have been one of the greatest running backs in nfl history, but then again, he's already considered among the best running backs. He was also a great kick returner. The problem with calling someone the greatest player in nfl history is that its really hard to compare players of different positions. In the NBA, the NHL, and in baseball, regardless of what position you play, you can still compare stats. In the NFL, you cant compare a RB to a QB, or a WR or any defender, it just doesn't work that way. So picking a single greatest is almost impossible to do.If I had to pick a single greatest player in NFL history, I would probably pick someone like Sammy Baugh. The thing that makes Baugh special was that he was a great quaterback, among one of the best ever, but was also a good defensive back and a punter. He played all sides of the ball, which is something we may never see again, not on a full time basis.