PORT ST. LUCIE, Fla. — On the last day of his first spring training with the Mets, Juan Soto said hello to some old friends: the Yankees.

With the Mets hosting their intracity rival Monday in their Grapefruit League finale, Soto had a chance to check off another item on his preseason to-do list, seeing his former teammates for the first time since he spurned them in December in free agency for a record 15-year, $765 million contract to come to Queens.

During pregame on-field socializing featuring the bunch of individuals who have spent recent time in both boroughs — including Carlos Mendoza, Omar Minaya, Luis Rojas, Marcus Stroman and Pat Roessler — Soto was in the middle of everything. If there were any hard feelings stemming from his momentous offseason decision, they did not reveal themselves amid the joviality.

“I told him he looks terrible in that uniform,” Yankees manager Aaron Boone joked. “Good to see him. Obviously, Juan was great for us. Just as important, he was a great guy in our room, great guy in our clubhouse. Honestly, it was actually really good to see him and just catch up for a minute.”

Soto said: “We have a lot of memories from last year. Just to get to see them and see that they’re doing well as a team and personally, too, I’m really happy for them.”

As Soto stepped to the plate in the bottom of the first inning, boos from the Yankees fans drowned out cheers from Mets fans at a sold-out Clover Park. Soto implied he did not hear it.

“I think it was a lot of cheers out there,” he said, not incorrectly. “I was happy for Mets fans who cheered for the players.”

Soto & Co. flew to Houston afterward, set for a workout day Wednesday ahead of Opening Day on Thursday. Other than being the new superstar in Flushing, he had a happily uneventful camp. He hit .289 with a 1.049 OPS (and four home runs), played plenty of rightfield, did what he considered productive defensive work with outfield coach Antoan Richardson and made it through healthy.

“We are really loaded as a team,” he said. “I can’t wait to see these guys going out there.”

In recent months, Soto has kept up with the Yankees’ goings-on, he said.

“What we did was special,” Soto said of their World Series run last year. “We feel like brothers right now. I keep in touch with a lot of guys over there.”

The next time Soto sees the Yankees will be May 16, the Subway Series opener at Yankee Stadium.

What will fan reaction be like that night?

“It wasn’t great out there today,” Stroman said. “You know New Yorkers, man. I’m sure it’s not going to be great. But you’ll never catch me booing him. But that makes it fun, too. He’s someone who eats that up, too. Sometimes you want to let a sleeping bear lie.

“You don’t want to get that guy riled up. He’s the last guy you want to get riled up, because when he gets riled up, he locks in better than anybody in the world. Maybe don’t boo. Maybe just be silent.”

Soto said with a smile: “You know Yankees fans, they can surprise you with anything. I’m expecting the worst.”

Notes & quotes: The Mets tied the Yankees, 6-6, as Brandon Nimmo hit a three-run home run in the ninth. The Mets finished their Grapefruit League schedule with a 13-13-5 record . . . The Mets drew 106,027 fans to their home exhibition games, a franchise record . . . The crowd of 8,088 on Monday was the second-largest single-game total since the Mets moved here in 1988. The only game better attended: Mets-Yankees in 2015 (8,175) . . . Francisco Lindor was demonstrably pumped up about an opposite-field single he bounced through the left side of the infield in his last at-bat. That upped his spring training average to .200 . . . A.J. Minter pitched for a second time in three days, perhaps his final hurdle to starting the season on the active roster after hip surgery last August . . . Mark Vientos said he has had no contract extension discussions with the Mets but is open to it. “I love playing with the Mets. I’m all ears,” he said. “In the meantime, I’ll keep playing, keep smiling, keep using my cool glove.” He recently debuted a new mitt featuring lettering of comic book-style onomatopoeia.

 With Anthony Rieber