PORT ST. LUCIE, Fla. -- A few days before Johan Santana arrived at Mets camp, manager Carlos Mendoza learned that one of the team’s top starting pitchers, Sean Manaea, had grown up idolizing him. So Mendoza plotted with Santana, sequestering him away until Manaea arrived at Clover Park on Saturday. When he did, Santana approached him at the breakfast table and extended his hand.

Manaea looked up to see his childhood hero looking back at him.

“Thirteen-year-old Sean was geeking out,” Manaea said. “Thirty-three-year-old Sean was, too.”

The two later had a lengthy conversation about pitching, with Santana explaining to Manaea how he threw his signature changeup. It was an interesting conversation; in today’s world of split-changes, kick changes and changeups thrown in the low 90s, Santana’s circle change -- so named because of the circle that a practitioner’s thumb and index finger make on the ball -- has become a bit of an anachronism. Modern tracking systems, Manaea said, probably wouldn’t think much of the pitch.

But Santana’s conviction in throwing it, as well as his consistent ability to execute it, made it devastating. That kind of stuff translates, even today.

“I believe in evolution,” Santana said. “But you still have to hit it. You still have to run. You still have to catch it. You still have to throw it. … At the end of the day, it’s a human being that goes on the hill to compete. At the end of the day, the essence is still, I think, the same.”

Although the Mets bring former players back to Port St. Lucie every year to serve as guest instructors, Santana had served in that role only for the Twins, never the Mets. But as his children have grown, Santana has begun considering life as an empty nester. He’d like to be more involved in baseball again, which is why he accepted Mendoza’s offer to drive across Florida from his home in Fort Myers. Santana intends to return next month.

In addition to working with Manaea and David Peterson, the two lefties in New York’s rotation, Santana spent time during this trip speaking to players on the Minor League side.

“Impactful,” was how Mendoza described the visit. “Every time you can get a player with his experience and knowledge -- not only for Sean, but for everyone here in camp -- there’s a reason why not only us, but a lot of teams are doing it.”

Later this spring, former Mets Carlos Beltrán, Darryl Strawberry, Dwight Gooden, John Franco and David Wright will report to camp, with all but Wright, who prefers being out of uniform, serving as guest instructors. Sometimes, those sorts of visits can be mostly ceremonial. Santana’s was not; he legitimately came to teach. At 45 years old, he’s not far removed from pitching in the big leagues himself, and he’s been molding himself as a leader of men. In his free time, Santana serves as the junior varsity coach for his son’s high school baseball team in Fort Myers.

The difference between high schoolers and big leaguers, the left-hander said, was that the big leaguers actually tend to listen.

“It’s cool when you have the greats just handing out knowledge like that,” Manaea said.

Going forward, Santana isn’t sure if he’d like to become involved with a team in a more formal way -- perhaps as a pitching coach. What he does know is he enjoys being around baseball and talking to players. He believes his experiences as a two-time Cy Young Award winner -- not to mention the only Mets pitcher to throw an individual no-hitter -- can help.

Plus, his signature pitch never goes out of style. Changeups are about as old as the game itself, even if their form and function have changed over the years.

“Maybe,” Manaea said laughing, “I’ll have a good changeup this year.”