Frank Vatrano knew Chris Kreider before he even joined the Rangers as a trade deadline acquisition in March 2022.

Vatrano’s cousin, Barry Almeida, played with Kreider at Boston College.

Having come within two wins of reaching the Stanley Cup Final with Kreider and the Rangers three years ago, Vatrano — who opted to join Anaheim as a free agent the following summer — understands better than most the value of the 13-year veteran acquired by the Ducks.

He is now the one welcoming Kreider into a new organization.

“When I arrived in New York, he texted me immediately, offering his place in the city for me to stay,” Vatrano recounted about Kreider from their time as teammates with the Rangers before both took part in the Shoulder Check Showcase at Terry Conners Rink in Stamford, Conn., on Thursday.

“It was incredibly generous of him. He didn’t ask for rent or anything. I was living large in Tribeca. It was fantastic. I’ll be eternally grateful for that. Now, having the opportunity to play with him again is going to be amazing. I understand that after being with one team for so long, transitioning isn’t easy. But he’ll be joining us where he already knows me, [Jacob Trouba], and [Ryan Strome]. California offers a more relaxed vibe, where you can keep a low profile. It’s an excellent place to raise a family, with beautiful weather every day, so he’s going to love it.”

Primarily skating on a line with Kreider and Mika Zibanejad for the 42 total games he played for the Blueshirts, Vatrano likes to say he was just “along for the ride.”

But he had a front-row seat to watch Kreider reach 52 goals during the 2021-22 season.

“His jersey is going to be hanging up at MSG some day,” Vatrano quipped.

Kreider looked content and at ease at Thursday’s charity event, which he has gotten several Rangers involved in to promote mental health awareness in memory of the late hockey player Hayden Thorsen.

Fans lined up against the fencing to the players’ entrance as early as 2:30 p.m. despite a 4 p.m. start time. There were several Rangers fans in attendance who were specifically looking to see Kreider, who held the title as the longest-tenured player for quite some time.

Asked if he felt weird, or if his June 12 trade to Anaheim had really set in yet, Kreider said yes and no. Some days yes, he said, some days no.

When it came to the fans, however, the exchanges were completely mutual.

“A lot of kindness, a lot of appreciation, a lot of gratitude — and that goes both ways,” Kreider said. “Super lucky to have experienced what I experienced, something that’s always going to be near and dear to me and a massive part of that is obviously the fan base. That’s what makes the Rangers so special, right?”

Sporting a scar on his hand from the surgery he underwent after the season, Kreider seems ready to endear himself to a new franchise.

While he’s continued to work out in the area, with his former Rangers teammates still in his vicinity, the next chapter in Kreider’s career is steadily approaching.

On Thursday at a small rink in Connecticut, however, the fans got to say goodbye.

“I think just his work ethic, the way he goes about his business every single day,” Vatrano said of what Kreider will bring. “He’s an absolute animal in the gym, and works hard every single shift. I think, for us, we have such a young team, we have such a balance. … Probably eight guys over the age of 23 and we have another seven or eight guys who are over the age of 30. There’s a good balance and we all get along.

“We’re always including each other in everything, going to dinners and stuff. He’s going to be a big part of that with our group going forward.”