Dillon Gee is now expected to miss three starts before returning from the disabled list, Sandy Alderson told reporters Tuesday at Citi Field.
Gee was put on the DL with a strained right lat muscle May 11, at which time the team said he would miss two starts.
Gee told reporters he plans to throw from flat ground this Wednesday and intends to make at least one minor-league rehab start before returning from the disabled list.
Jacob deGrom was originally promoted from Triple-A to pitch in the bullpen, but immediately stepped in to the rotation for the injured Gee.
Gee was 3-1 with a 2.73 ERA in eight starts with the Mets before his DL stint.
DeGrom allowed just one run and four hits in a 91-pitch, seven-inning big-league debut last week against the Yankees.