Manager Mickey Callaway said the team decided to shut down deGrom as a precautionary measure. On Saturday, the Mets had said deGrom would take his regularly scheduled turn in the rotation.
"The more and more we thought about it, we have to make sure that he's totally fine,'' Callaway said. "He feels no pain and he wanted to pitch tomorrow.''
Left-hander P.J. Conlon was recalled from Triple-A Las Vegas to take deGrom's spot in the rotation against Cincinnati. Conlon, 24, is 1-2 with a 6.75 ERA in five starts this season. Last season, at Double-A Binghamton, he was 8-9 with a 3.38 ERA.
DeGrom is 3-0 with a 1.87 ERA in seven starts for the Mets, who entered Sunday's game against Colorado at Citi Field in the throes of a five-game losing streak. Last season, he went 15-10 with a 3.53 ERA and 239 strikeouts and finished eighth in National League Cy Young Award balloting.
"I said I felt like I could go, but I think the bigger picture is what we're looking at,'' deGrom said. "If you go out there and something happens, you end up missing five starts, vs. skipping one and making sure everything is fine. After talking to them, I understand the decision. Erring on the side of caution is what we're doing.''
DeGrom is scheduled to throw a 50-pitch bullpen session Tuesday, with intermittent rest to simulate real game conditions. If all goes well, he will throw a bullpen session Friday before his next start.
DeGrom injured himself while swinging a bat in the third inning of Wednesday's 7-0 loss to the Atlanta Braves, and Callaway has said the Mets prefer that he do nothing more strenuous than bunt when he returns to the rotation. DeGrom, a .190 career hitter, is batting .143 (2-for-14) this season.
"I haven't been hitting the ball very well anyway,'' deGrom said. "Seriously, I'd much rather be out there pitching. So if I can't swing -- whatever. I'd much rather be able to go out there and compete and keep us in a ballgame.''