Ramos traveled back to New York on Sunday to be seen by a doctor. The right-hander told the club about the tightness after allowing three runs and three hits while getting just two outs in a 17-6 loss Saturday to the Milwaukee Brewers, assistant general manager John Ricco said.
Ramos has given up eight runs in his last 4⅔ innings. He also walked consecutive batters in a 4-3 loss to Milwaukee in 10 innings on Friday, skipping a 3-1 fastball into the dirt to force in the winning run.
"He's struggling throwing the ball where he (wants) to, that's the first sign something's going on with somebody. We were wondering if that might be the case," manager Mickey Callaway said.
A former All-Star acquired at the trade deadline last year from the Miami Marlins, Ramos was expected to play a key role again in the back end of the Mets' bullpen.
Instead, his struggles have contributed to a taxed pitching staff in the middle of a busy stretch of the schedule. The Mets travel to Atlanta next for a four-game series that starts with a doubleheader Monday.
They optioned Chris Flexen to Triple-A Las Vegas before the series finale against the Brewers on Sunday and recalled P.J. Conlon. Callaway said Conlon could be an option to start the second game of the doubleheader on Monday if the left-hander isn't needed against Milwaukee.
The club also planned to fly pitchers Hansel Robles and Gerson Bautista, along with catcher Kevin Plawecki, to Atlanta "to give us some options for the doubleheader," Ricco said. The Mets would have to make more moves to get them on active roster, with Robles (right knee) and Plawecki (left hand) currently on the disabled list and Bautista assigned to the minors.
Mets management also has been discussing the future of struggling left-handed starter Jason Vargas, who gave up five runs and six hits in three innings on Saturday. His ERA ballooned to 10.62.
The Mets signed Vargas in the offseason to a two-year, $16 million contract. He went 18-11 with a 4.16 ERA for Kansas City last season, making his first All-Star team and tying for the major league lead in wins.
When asked, Ricco said he thought Vargas could be successful in the bullpen if needed but preferred that he start.
"Obviously the best thing for us is him being a productive pitcher, the guy that won 18 games for us last year," Ricco said. "But we have to consider what's best for this team as well. We're talking about a lot of different options."