JUPITER, Fla. — Mets ace Matt Harvey has been shut down for the remainder of spring training, casting doubt on whether he can make his Opening Day assignment, because of a medical ailment that the club has refused to disclose.

Aside from insisting that the issue is non-orthopedic in nature, general manager Sandy Alderson and manager Terry Collins offered only shards of information regarding the pitcher’s condition. Alderson labeled it “a non-baseball medical issue that we have to address.”

“He had a symptom,” Alderson said on Monday. “It was investigated, so we’re still in that process.”

Harvey was excused from Monday’s game against the Cardinals so he could be examined by doctors. Initially, a team spokesman said Harvey was still scheduled to pitch on Tuesday against the Marlins, his final tune-up before the regular season.

But following the game, Collins said the righthander had been scratched with an issue that he said “popped up recently.” While Collins said it’s possible that Harvey still makes his Opening Day start even without appearing in another exhibition game, he was noncommittal when asked about his level of concern.

“It’s hard to say right now,” Collins said. “I don’t know just yet. What I do know, we’re very lucky to have the pitching we’ve got. In case he can’t go, we’ll have somebody else ready.”

Alderson said it’s possible that Harvey will return to New York for further tests, though as of Monday afternoon, the pitcher remained in Florida.

“It’s a little early to attach any level of concern,” Alderson said. “We need to wait for more medical information before we decide if it’s of concern or grave concern or no concern.”

As for Opening Day, Alderson said it was too early in the process to begin planning for contingencies.

“I’m not getting into that,” Alderson said. “It’s way too premature for us to be discussing anything related to Opening Day. I understand Opening Day is not too far away but we’re dealing with tomorrow and we should know something more tomorrow or the next days. But right now, he’s not pitching tomorrow.”

Harvey, who turned 27 on Sunday, is entering his second full season since undergoing Tommy John surgery. But the Mets were insistent that his medical condition did not stem from his elbow.

“It is not orthopedic,” Collins said. “His arm is fine.”