Mike LaFleur wore a postgame smile Sunday that was seldom seen when he called MetLife Stadium his full-time home.

The Rams offensive coordinator punctuated a successful cross-country return by celebrating quietly with his family in the bowels of the stadium after a 19-9 victory against the Jets.

LaFleur was fired as Jets offensive coordinator after the 2022 season — reportedly at owner Woody Johnson’s behest — but wound up making an immediate semi-lateral move to the Rams, where he doesn’t call plays but is part of a winning culture established by Sean McVay.

Jets stars Garrett Wilson and Breece Hall were rookies during LaFleur’s second of two seasons trying to develop quarterback Zach Wilson and both made a point to catch up with their former coach on the field.

“My rookie year, looking back on it, it was a special time and I might’ve taken it for granted,” Wilson said. “I love him. To see how he is helping out that offense and watching them today with their plan to run the ball and the way they executed, I’m happy for him. I hope it continues to take place throughout the playoffs because I really do appreciate him.”

Wilson and Hall have remained in regular contact with LaFleur.

The Jets were near the bottom of the NFL, averaging 17.8 points per game during LaFleur’s two years calling plays on head coach Robert Saleh’s staff.

Since Saleh replaced LaFleur, the Jets are averaging 17.5 points under both Nathaniel Hackett and the demoted Hackett’s in-season replacement Todd Downing despite swapping in Aaron Rodgers for Wilson.

The Rams only had 242 yards of offense against the Jets but had the clear sideline advantage.

“I look around and there’s not too many familiar faces from [2022],” Wilson said. “That’s how it goes when you don’t win games. Just those relationships and the way that we could talk to each other and the way certain things were.”

McVay calls plays for the Rams — as many offensive-minded head coaches around the league do — but LaFleur has a key role in game-planning.

McVay’s coaching tree — a branch of the bountiful Shanahan coaching tree — is becoming a go-to for general managers looking to hire.

Hall had the best season of his three-year career under LaFleur.

“We have a group chat with Garrett where we are always joking around,” Hall said. “He’ll just text us and ask us how we are doing every now and again. It’s cool to maintain a relationship with a guy we were only with for one year but was one of the pivotal guys in our careers to give us confidence and trust to put the ball in our hands.”