It all comes full circle.

The Mets acquiring Marcus Stroman surprised many — at six games out of the wild card as of Monday night, the Mets were expected to be sellers at the deadline, not buyers. The Mets’ plan and Stroman’s fit and future with the team remain hazy at best. His former coach, however, thinks he’ll do just fine.

“He’s a great pitcher,” Stroman’s high school coach, Anthony Frascogna, told The Post. “Obviously the Mets have good pitching already, and it just got better. He’s gonna fit it in and compete for whatever team he’s on.

“He’s not gonna shy away, wherever he goes he’ll fit it. He’ll be a leader in the clubhouse — guys like him. He’s just one of those guys. He’s gonna try to win whatever he’s doing. Whether he’s with the Mets or wherever he is, he’s gonna fit in, I’m sure. People want people that win.”

Stroman, a 28-year-old Long Island native, attended Patchogue-Medford High School, where Frascogna coached him in JV football and varsity baseball. Frascogna will enter his 20th season as head coach of the varsity baseball team this spring, and says Stroman is the best player he’s come across. He recalled the sense of confidence his team had whenever Stroman pitched, knowing one run would often be enough for a win.

In the majors, Stroman hasn’t backed down from his demonstrative and emotional style of pitching, a characteristic that will now be under a bigger microscope in New York. It’s a part of his game that has helped make him an All-Star, according to Frascogna.

“He always had a chip on his shoulder,” Frascogna said of Stroman, whose preference was to play for the AL East-leading Yankees. “He definitely used whatever negativity there was out there to his advantage, whether it was actual negativity or imagined negativity, he would use it. He played with a passion. We could be playing a game of two-ball or whatever, and he would play to win.”

Frascogna’s favorite memory of Stroman is one that connects him with his new team — a pitching duel between Stroman and new teammate Steven Matz, who was starring for rival Ward Melville High School. Matz came out on top — a 1-0 epic that has gone down in Long Island lore.

“The biggest [memory], and it’s obvious as it comes back to light today, is the one when he faced off with [Steven] Matz in high school,” Frascogna said. “Even though that was a loss for us, that was just one of those things that was kind of bigger than the game — two Long Island kids getting drafted. We had 50 scouts at the game, it was crazy.”

The first text Frascogna received after news of the trade broke was from Matz’s former coach, Lou Petrucci. Now, 10 years after that epic matchup, they plan to watch their former players together at Citi Field.

For Stroman, and those who knew him at a young age, it has all come full circle.