The 25-year-old Erlin had a 4.02 ERA in three appearances and two starts this season, including allowing just one run over six innings in a 3-0 loss to the Phillies on April 12.
Erlin was touched for six runs in six innings against the D-backs on April 17 and was placed on the disabled list four days later.
Worth noting • Catcher Hector Sanchez is expected to report to the Padres on Friday. Claimed off waivers from the White Sox on Wednesday, Sanchez will give San Diego three catchers on its 25-man roster.
"With [Austin] Hedges on the DL in the Minor Leagues, we don't have a lot of catching depth in the organization," Green said. "It was a chance to acquire a switch-hitting catcher at a very low cost. He's a good receiver and has a good feel for the game. "It probably gives me the liberty to probably pinch-hit Christian Bethancourt a little bit more. I'd like to use him as a pinch-hitter from time to time and haven't been able to do that."
• It is unclear if right-hander Andrew Cashner will make his scheduled start on Saturday against the Brewers. Cashner left his last start due to cramping in both hamstrings.
"I don't know the answer to that right now," Green said. "He's going to move around [Thursday] to see how he feels."
Andrew Gruman is a contributor to MLB.com and is based in Milwaukee.