Diaz (neck) will embark on a rehab assignment before returning from the injured list, Jack Harris of the California Post reports.
Diaz threw a simulated inning Tuesday and will do so again later this week before joining one of the Dodgers' minor-league affiliates. It's unknown how many rehab innings the 32-year-old will pitch before rejoining Los Angeles' bullpen, but once he's healthy, he is expected to pitch in lower-leverage situations until the Dodgers are comfortable moving him back into a closing role.