Growing pains can end for former UFC champion Chris Weidman or Southland’s Kelvin Gastelum

“Growing up” would’ve been the ideal marketing slogan for Saturday’s UFC Fight Night card on Long Island in New York between native son Chris Weidman and his Southland opponent, Kelvin Gastelum.

For former middleweight champion Weidman, returning for the Fox-televised (5 p.m. Pacific) card at the renovated former Nassau Coliseum is a journey back to the venue where he used to attend New York Islanders games.

“To have the first one in Long Island and be in the main event, it’s a dream I never dreamed,” Weidman (13-3) said. “When I grew up going to Islanders games, waiting for them to come outside for autographs, if anything, I dreamed of being an Islander.”

Weidman’s work as an informal UFC lobbyist helped the organization win regulation approval in the New York Legislature last year after an intense effort.

Gastelum, meanwhile, says that after having a March victory over former UFC champion Vitor Belfort changed to a no-contest because of a positive test for marijuana, meeting Weidman is a chance to show his maturity.

The 25-year-old Gastelum (14-2) has previously missed weight.

“In the long run, it’s about making better choices and being smarter,” Gastelum said. “I’m only 25 and I feel like I’ve matured and grown a lot since I’ve been in the organization. There is no handbook, no protocol on how to live this life. It’s a matter of persevering through your problems and keep on keepin’ on.”

Weidman can relate after losing his belt to Luke Rockhold in late 2015, then suffering New York losses to Yoel Romero and Gegard Mousasi.

Gastelum “came up and beat some good guys and is a well-rounded kid, but I don’t think he’s fought anyone like me yet,” Weidman said. “The size, the length, the wrestling, the judo … I think I pose a lot more threats to him than he does to me. And I’ve fought higher-level competition than him for way longer, gaining more experience.”

Huntington Beach’s Gastelum said victory will springboard him nearer to a shot at the middleweight belt worn by veteran Michael Bisping, who’s recovering from a knee injury while waiting on medically suspended Robert Whittaker.

“Mentally, whether [Weidman] wants to admit it or not, I feel he’s in desperation mode, which makes him very dangerous,” Gastelum said. “We’ll see one of the best Chris Weidmans for this fight, with him in front of his friends and in his backyard. But I am very confident in my preparation.

“I feel like I’m almost there. No one is perfect. We’re making the right assessments and changes and having the right people around me. I think that will make a difference.”

As for Weidman, his path back to a title shot requires victory near where his hockey ambitions rested.

“In college, right before I was crossing over to MMA at Hofstra, I wanted to give hockey one more shot because I was good when I was younger and I felt I knew how to win and get good at things,” Weidman said.

“So I bought all this new hockey equipment and went out to the rink, even though I hadn’t played since sixth grade, and I learned quickly it’d take a lot more time to be at the NHL level, so I gave up on that.”

lance.pugmire@latimes.com

Twitter: @latimespugmire