Even Dan Marino listened as Jerry Schuplinski talked for an hour.

One day during the Dolphins’ minicamp last spring, quarterbacks Ryan Fitzpatrick and Josh Rosen, offensive coordinator Chad O’Shea, head coach Brian Flores and a Hall of Famer just passing by all tuned in to the assistant quarterbacks coach as he installed a practice plan.

“Jerry was the only one who spoke,” recalled Greg Debeljak, Case Western Reserve University’s head coach and a face in the crowded meeting. “He can really take charge of a room and teach. There was film and X’s and O’s, and every once in a while Jerry would look back to Marino: ‘What do you think, Dan?’ He would go, ‘Looks great, coach!’ ”

Schuplinski is the new Giants quarterbacks coach, handed the franchise’s greatest asset to develop. The Giants slow-walked the search to land Jason Garrett as offensive coordinator but acted fast to hire Schuplinski, who will be one of the primary coaches entrusted to elevate Daniel Jones from promising rookie to elite NFL quarterback.

So, who is he?

“I got to see it from two different sides,” the 14-year veteran Fitzpatrick told The Post. “He had to talk to me, treat me and coach me a different way than maybe he had to treat young guys like Josh Rosen and Jake Rudock in our room. His ability to know who he was teaching and the way that guy learned — and adapt based on who he was talking with — is one of his huge strengths.”

First-time head coach Joe Judge wants great “teachers” above all else on his Giants staff.

Apparently, Judge means it literally: Schuplinski was a math teacher, coach and athletic director at Trinity High School in Garfield Heights, Ohio, from 2002-06. The 38-year-old Judge — who quit teaching kindergarten after three days — and Schuplinski worked together for six seasons (2013-18) with the Patriots.

“He is an intelligent guy who was very well-liked,” said Tony SanFilippo, Trinity’s athletic director and the private school’s wrestling coach during Schuplinski’s tenure. “Meticulous and detail-oriented. When he came here, he was honest with our administration. He had high aspirations.”

Schuplinski, Patriots offensive coordinator Josh McDaniels and Patriots director of player personnel Nick Caseiro — a future NFL general manager — played together at John Carroll University in the mid-1990s. Debeljak was the wide receivers coach then and later gave the undersized fullback Schuplinski two of his early breaks in coaching.

While McDaniels drew up Tom Brady’s game plans, Schuplinski’s Patriots résumé wasn’t truly on display until this season. Colts starter Jacoby Brissett and 49ers starter Jimmy Garoppolo credit Schuplinski for easing the learning curve when they were young Brady backups.

“It worked well with me because he sees the game as a quarterback,” Fitzpatrick said. “It’s not just understanding what we do at wide receiver, tight end or offensive line. He understands conceptually everything that’s going on, which sounds simple but there aren’t a lot of coaches who see it that way.

“He does a great job of slowing things down and explaining on each play the pre-snap keys, what’s happening post-snap. We have to process so much information at the line of scrimmage that finding ways to simplify it and little cheats to speed up the way you are thinking about things, he does a nice job of teaching it that way.”

Schuplinski’s first coaching job was an unpaid graduate assistant position at his alma mater. He spent five years as special teams coordinator and linebackers coach at Case Western Reserve before McDaniels swooped in.

“His goal when he left here for the Patriots was to absorb as much as he could — and that’s what he did,” Debeljak said. “That’s when he got his education in quarterbacks.”

Schuplinski joined the Dolphins in 2019 and stepped in to lead the quarterbacks for Jim Caldwell when the former NFL head coach took a health-related leave of absence. Flores, another former Patriots assistant, did not block Schuplinski’s move to the Giants, which he could have done under NFL rules.

“More so than being a football-lifer, he is an educator,” Fitzpatrick said. “For me, as a veteran guy who has had a ton of quarterback coaches, he understands the game really well so we were able to talk about it at a pretty high level. It’s a tough loss for the Dolphins, but I think it’s a great move for New York.”

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