Too many variables/unknowns to put a time frame on it. "Broken bone in hand". Which bone? Which hand? Fractured or broken?
I suspect that with his talent, along with inexperience they'll bring him along slowly. I think he'll be a great player. IMHO he's the best running back talent we've had since Shelton or Bush. Long term view says don't throw him into the fire if it's too early. Reggie is capable (providing the line does their job). Slowly add Wilson to the mix and you have a deadly backfield with Lamar, Wilson and Reggie (who is VERY capable of throwing the ball). Remember, Reggie has a win at Notre Dame as the starting QB. The possibilities are scary if things are integrated at the right time.