Williams will start Thursday's preseason contest against the Falcons, Adam Beasley of the Miami Herald reports.
The Dolphins backfield is sans Jay Ajayi due to a concussion, handing Williams the initial running back reps. In three seasons, he's only managed 3.4 YPC, but his prowess as a receiver is notable, as he's racked up 65 catches (on 87 targets) for 578 yards and five touchdowns.