Ball should scare people in the same way Barkley scares people. Ball comes from a school that always produces big numbers for their running backs but the RB's never really pan out in the NFL (Dayne/Fletcher/Clay/Hill/White/Moss). All of them are tough physical runners that thrive behind HUGE offensive lines but their lack of speed/quickness limit them in the NFL.
Not suggesting that Ball should be ignored or avoided, but he really needs to impress me in the combine to convince me he is worth a 2nd round pick. If you want a guy with similar skill set that you can probably snag later in the draft look at Le'veon Bell from Michigan State.
Personally, I would use the 2nd round pick on a guard. Try to swing a trade and get a couple of extra 5th round picks and take guys like Le'veon Bell and Ray Graham who reminds me of Ray Rice.