Ballard tore his ACL in a freak accident and the Colts will now have to rely on Ahmad Bradshaw and Donald Brown to take up the reins in the running game, unless general manager Ryan Grigson can execute a trade.
Irsay wrote on Twitter: "We're all hurting for Vick BaL. Bradshaw, Brown and others must step up. Grig's gonna work hard to wheel n deal B4 trade deadline, let's roll."
Indianapolis face the Miami Dolphins on Sunday.