I agree a move to WR is doubtful, as Kelly noted he lacked ball skills, which I think is coach speak for not good hands/cant find the ball/etc.
As a RB, its not his height that is the main concern, its that he "runs like he is on skis" according to one poster. He lateral movement is not great.
He does look tremendous when a large hole is opened up, as he has great speed. Against the Navy type teams, he might run for a great YPC, but against a tough D, I dont see him getting the most carries.