NEW YORK -- Acknowledging that the situation is “still fluid,” manager Carlos Mendoza revealed on Thursday that J.D. Martinez is unlikely to make his Mets debut when first eligible on Sunday in Cincinnati.

Martinez will, however, shift his ramp-up program from the back fields to one of the Mets’ Minor League affiliates as soon as Friday. Previously, Martinez had been working out at the team’s Spring Training complex in Port St. Lucie, Fla.

Team officials at least discussed the option of Martinez joining the Mets without first appearing in any Minor League games, but that option is no longer on the table. Mendoza said Martinez has had days in Florida where his “mechanics are off, timing is off.” The club also wants to see the 36-year-old run the bases to test his conditioning in real games before making it back to the Majors.

“This is a very meticulous guy,” Mendoza said. “He knows his swing. Very detail-oriented. But he’s getting a ton of at-bats, and the feedback we’re getting … he’s moving in the right direction.”

Upon signing a $12 million contract with less than a week left in Spring Training, Martinez consented to having the Mets option him to the Minors so he could go through something approximating a normal Spring Training progression. By rule, that meant he had to stay in the Minors for at least 10 days -- a waiting period that will expire on Sunday.

But New York doesn’t plan to fly him to Cincinnati for the final game of a three-game set against the Reds. Mendoza did acknowledge that Martinez could join the Mets in Atlanta for a four-game series that begins on Monday, but he wouldn’t commit to having Martinez available to face the National League East favorites.

“I know we’ve got Atlanta, but … at the end of the day, we want to do what’s best not only for J.D., but for the team,” Mendoza said. “Health is important here, making sure that we’re not rushing him, not putting especially a guy like J.D. at risk.”

A six-time All-Star, Martinez appeared in 113 games last season for the Dodgers, missing about three weeks due to a groin injury.

“He’s going to have a strong opinion on this,” Mendoza said. “He knows himself better than anybody else. His routine and how detail-oriented he is, the feel for his swings and mechanics and things like that -- we will consider those things and we’ll go from there.

“But he’s getting a lot of at-bats. He’s feeling good. And now we’ve got to take it to the next step.”

In a perfect world, the Mets would like Martinez to face some upper-Minors pitching at Triple-A Syracuse or Double-A Binghamton, but the frigid April weather in those locales could prompt them to keep Martinez sequestered at Single-A St. Lucie instead.

Syracuse has already endured multiple rainouts this season and could see snow showers this weekend in Scranton, Pa.

“A lot goes into when we’re trying to make these decisions,” Mendoza said. “You look at weather. You look at potential rainouts and things like that. You don’t want to miss any games. You want to keep him in warm weather. I think it’s a combination of a lot of things.

“But at the end of the day, as long as he’s getting at-bats and he’s running the bases, it’s more like a real game now.”