Coach Doug Marrone confirmed Monday that Spiller underwent surgery to repair his clavicle. Per ESPN's Mike Rodak, the Bills haven't decided yet whether or not Spiller will be placed on IR, but obviously the running back is out indefinitely. With Fred Jackson also in line to miss time, the team's Week 8 backfield will be headed by a combo of Bryce Brown and Anthony Dixon, with the Bills also considering adding another back to their practice squad.