Although undisputed RB1 James Cook has the ability to play all three downs, this is the age of running back by committee across the NFL. The Bills have some, but it wouldn't be a bad idea to add a proven, low-cost veteran who can step up in case of injury.
In terms of available free agents with proven tracks records, the market isn't exactly robust at this point in the offseason. Aging running back Latavius Murray, who played a role in Buffalo last year, has yet to sign and previously stated interest in playing at 34 years old. With all due respect to Murray, who cannot be knocked for his level of effort, the tread on the tires was worn thin down the stretch in 2023.