Diaz (neck) will begin a minor-league rehab assignment with Triple-A Oklahoma City on Sunday, Bill Plunkett of The Orange County Register reports.
Diaz last pitched for the Dodgers on Aug. 17, when he gave up three runs on four hits over one inning in Colorado. He landed on the injured list the next day with a diagnosis of neck inflammation. Diaz may not need an extended rehab stint, but even if he's fully recovered, he's expected to log lower-leverage work upon his return to the big-league club.