NEW YORK -- For a team built around a pair of ace pitchers, losing one to injury is difficult. Losing both could be cataclysmic.

Already playing the first half of this season without one of their aces, the Mets on Wednesday faced the prospect of potentially proceeding without another. Max Scherzer left his start against the Cardinals in the sixth inning after feeling left-side discomfort on a pitch. He walked off the Citi Field mound alongside a trainer, and while Scherzer could only speculate as to the severity of his injury, he’s hopeful that he took action in time to avoid the worst.

Scherzer underwent an MRI on Thursday morning to receive an updated diagnosis and timeline. The Mets are waiting for all the appropriate doctors to read it before issuing an update.

“I don’t think this is a major strain,” he said after the Mets’ 11-4 win over the Cardinals. “I was kind of tight, and then all of a sudden it went. But I don’t feel like I really ripped it. I felt like it just kind of got worse. So hopefully I got out of there quick enough to prevent a major, major injury here. I know obliques, intercostals, those things can be nasty. Hopefully, I avoided a serious injury.”

Making his eighth start since joining the Mets on a three-year, $130 million contract, Scherzer grimaced upon throwing an 85-mph slider in the dirt to Albert Pujols. Almost immediately, he called for trainer Joe Golia, who came to the mound alongside manager Buck Showalter and pitching coach Jeremy Hefner. The group conferred for a few moments before Scherzer walked off alongside Golia.

Showalter likened the situation to the final days of Spring Training, when Scherzer scratched himself from his final Grapefruit League start due to right hamstring tightness. He wound up recovering in time to start the second game of the season, one day after he would have otherwise pitched. Scherzer also removed himself from last year’s National League Championship Series Game 6 due to an “overcooked” right arm, and he has come out of starts due to groin and neck issues in the past.

“He’s been a great self-evaluator,” Showalter said. “He knows when he’s at a point when if he pushes more, it’s going to turn into something serious.”

“I just felt a zing on my left side and knew I was done,” Scherzer added. “We don’t know exactly what the injury is, but I’ve never had a left-side injury before. So when I felt it, I knew, ‘There’s no way you can throw another pitch, so just get out of there.'”

Asked if this is more a day-to-day or week-to-week situation, Scherzer replied that he has “no idea right now,” calling it “foolish to even think anything” until he’s received his MRI results. Those should come back by the time the Mets head to Denver for a three-game series against the Rockies this weekend. Scherzer was never scheduled to pitch in that series, but he would be lined up for Monday in San Francisco if healthy.

The Mets can ill afford a lingering injury to Scherzer, particularly with both deGrom and Tylor Megill already on the injured list. deGrom, who was diagnosed with a stress reaction in his right shoulder in the final week of Spring Training, isn’t due back until probably July. Megill is dealing with right biceps inflammation and currently shut down from throwing.

The rest of the Mets’ rotation includes Chris Bassitt, Carlos Carrasco and Taijuan Walker, with David Peterson and Trevor Williams as depth options. Should Scherzer miss time, it’s likely that both Peterson and Williams would take turns the next time through the rotation.

“We don’t wallow around in self-pity,” Showalter said. “Nobody cares about your problems. Our fans do, but the people we’re competing against don’t care. And we like the people that we’ve surrounded ourselves with. Nobody has the track record of Max, but this is not a sky-is-falling team.”

Still, most clubs are built to withstand only so many injuries. In deGrom’s absence, Scherzer had been the rotation linchpin, entering Wednesday’s play with a 4-1 record and 2.66 ERA. He allowed two runs to the Cardinals -- both on a Pujols single -- before departing, to improve to 5-1 with a 2.54 ERA.

The Mets made certain to take that positive out of the night, using Pete Alonso’s three-run homer to spark a five-run rally in the eighth. Afterward, they were concerned for their ace but confident in their ability to trudge forward regardless.

“He’s a bulldog,” Alonso said. “I know he loves to compete, but also at the same time, he’s really smart. If he were to keep pushing and keep going, something a lot worse could have happened.”