Mets put Christian Scott on IL with UCL sprain in worrying sign

Just as the Mets are adding an arm to the starting rotation they have subtracted another.

Christian Scott was placed on the injured list Monday with a sprained ulnar collateral ligament in his right elbow, leaving a question mark as the team is preparing to deploy a six-man rotation with Kodai Senga’s scheduled return on Friday.

The 25-year-old Scott, according to manager Carlos Mendoza, had soreness in the elbow during his start in Miami on Sunday and it persisted a day later, prompting the team to send him for an MRI exam on Tuesday.

Before the Mets opened the second round of this season’s Subway Series , Mendoza said it’s still unclear if Scott — who dealt with elbow issues last season in the minor leagues — will need Tommy John surgery that would likely sideline him until 2026.

“There is always fear,” Mendoza said at Yankee Stadium, when asked about Scott potentially needing surgery. “Especially since this is something he dealt with last year as well, but we are still waiting. We are going to have multiple people take a look at him before we make a decision.”

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Scott, according to a source, was found to have damage in the ligament last year and the Mets knew it would be an issue going forward.

The Mets brought up Scott quickly this season in part so he could use his bullets in the major leagues rather than the minors if the ligament again became an issue.

The rookie Scott has started nine games for the Mets this season and pitched to a 4.56 ERA.

In his Sunday start against the Marlins he allowed a three-run homer to Jazz Chisholm Jr. and was removed after four innings and 75 pitches.

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Scott began the year as the organization’s top pitching prospect after a breakout season at Single-A Brooklyn and Double-A Binghamton.

Scott was summoned to the Mets for his major league debut in May and spent three weeks with the team before returning to Syracuse. Scott rejoined the Mets’ rotation three weeks ago.

Mets officials have been judicious in monitoring Scott’s pitch count in part because of his elbow problems last season, according to Mendoza.

The Mets still plan to deploy a six-man rotation following Senga’s return on Friday, meaning somebody “will have to step up,” Mendoza said. Team officials are discussing whether Jose Butto (who has thrived in the bullpen ) can be easily transitioned back to the rotation. Tylor Megill, at Triple-A Syracuse, is another possibility.

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Senga was diagnosed with a shoulder strain early in spring training, but since then the Mets had been relatively fortunate in keeping their starting pitchers healthy: Luis Severino, Sean Manaea and Jose Quintana have all taken regular turns in the rotation and David Peterson also hasn’t missed a start since he returned in late May from his rehab from offseason hip surgery.

Butto has been a reliever since his recall from Syracuse on July 2 and Mendoza has at least some concern that he isn’t built up enough for an immediate return to the rotation.

There is also the issue of the Mets having a shortage of dependable relievers and Butto has allowed only one earned run in his six appearances since returning.

“It’s all part of it, but at the same time understanding the health of the player,” Mendoza said. “In Butto’s case, how far can we push him? It’s been almost a month since he’s thrown 100 pitches. We’ll factor all of this in the decision-making.”

Megill was bumped from the rotation and optioned to Syracuse in June following a rough stretch. The right-hander has started eight games for the Mets this season and pitched to a 5.08 ERA.

Pitching coach Jeremy Hefner recently told The Post a point of emphasis with Megill has been becoming more aggressive with two strikes to put hitters away.

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