Manager Gabe Kapler said after the game that Neshek probably would be put on the injured list.
"I'm not 1,000% sure, but it's likely," Kapler said of the injured list.
Neshek exited with a 2-0 count on Trea Turner in the eighth inning of the second game of a doubleheader Wednesday night. The submarine right-hander gave up a solo home run to Victor Robles and retired the other two hitters he faced in the 2-0 loss.
Neshek entered 0-1 with a 4.67 ERA in 19 games. He came off the injured list Sunday after missing more than three weeks with a shoulder strain.
Information from The Associated Press was used in this report.