ATLANTA -- The Mets will be without one of their most successful starting pitchers for roughly half the remaining season.

On Tuesday, an MRI revealed that Carlos Carrasco suffered a low-grade left oblique strain during his start the previous night. Injuries of that type typically require three to four weeks to heal, making it unlikely Carrasco will return until early to mid-September. The Mets placed him on the 15-day injured list before Tuesday’s game.

“We hope it’s not as long as some of those things take,” manager Buck Showalter said. “We’ll see.” 

Before departing Monday’s 13-1 loss to the Braves after two innings, Carrasco had given the Mets a noteworthy run of success on the mound, going 5-0 with a 1.69 ERA in seven starts from July 3-Aug. 9.

In Carrasco’s absence, the Mets are likely to slide David Peterson, who had already been scheduled to start one half of Saturday’s doubleheader against the Phillies, back into the rotation on a more permanent basis. Swingman Trevor Williams is scheduled to pitch the other half of that doubleheader against the Phillies. 

While Showalter wouldn’t commit to Peterson as the full-time replacement for Carrasco, he should fill that role for as long as he continues performing. Peterson, who rejoined the club Monday in Atlanta, is 5-2 with a 3.17 ERA as a starter. The Mets won’t officially activate him until Saturday; in the interim, relievers Stephen Nogosek and R.J. Álvarez joined the active roster to provide length out of the bullpen.

The Mets are trying to stay away from Williams as a reliever this week, given his impending spot start.

“It’s part of the depth that’s allowed us to have some consistency,” Showalter said of Peterson and Williams. “But let’s face it, Carlos has made more starts than anybody on our staff. I actually look at it like it’s an opportunity maybe to freshen him up arm-wise a little bit, because he was doing some things that nobody really expected him to do. You hoped he would, but I think he’s exceeded the things that we hoped he might do.”

Overall, Carrasco is 13-5 with a 3.92 ERA in 23 starts. He has been one of the Mets’ most improved players following an injury-plagued 2021 campaign that saw him make only 12 starts due to hamstring and elbow woes.

Of note, Carrasco’s contract includes a vesting option worth $14 million for next season if he reaches 170 innings. That will now be nearly impossible for Carrasco, who is at 126 1/3 innings and isn’t likely to make more than five or six starts the rest of the way. If Carrasco fails to reach that threshold, the clause will become a team option with a $3 million buyout.

Carrasco remains one of several candidates to make the back end of New York’s playoff rotation, along with Chris Bassitt and Taijuan Walker.