Williams (elbow) is slated to make his third rehab start Wednesday at Triple-A Rochester, Mark Zuckerman of NatsJournal.com reports.
After recording just two outs and yielding four runs (two earned) in his first rehab appearance June 28 with Single-A Fredericksburg, Williams bounced back nicely in his second minor-league outing Friday with Double-A Harrisburg. In that start, Williams struck out two batters and allowed just one hit and no walks over 2.1 scoreless innings. He'll look to get further stretched out Wednesday and is likely to need at least one more start in the minors following the All-Star break before the Nationals consider bringing him back from the 60-day injured list. The Nationals have gotten respectable results lately from Zack Littell, Miles Mikolas and Andrew Alvarez at the back end of the rotation, so it's unclear if the team will be willing to open up a starting role for Williams once he's ready for activation.