Jay Glazer has been involved in mixed martial arts since its primordial days, an era when seeing UFC 205 advertised on the Madison Square Garden marquee would have seemed unfathomable.

“It’s kind of like if I got involved in the NFL in 1925,” he said on Thursday. “These guys were doing clubs; my friends all of a sudden now are wealthy and famous and signing autographs. It’s kind of surreal that it’s all happened.”

Glazer is thrilled to be a part of it as host of FS1’s coverage, including the weigh-in on Friday and the pre-fight show, prelims and post-fight show on Saturday.

“This for me, being a New Yorker, being a guy who actually was doing this before it was legal here, it’s the Super Bowl,” he said of mixed martial arts at last becoming legal in New York State.

“I’ve always loved the sport. I’ve always felt a lot of people in team sports play it because they’re bigger, stronger, faster than everybody else. But this sport, 99.999 percent of the world is unable or unwilling to do it. So it’s special. It’s different. It makes you different.”

Glazer, 46, began fighting when he was covering the Giants in the 1990s and later trained others, including NFL players, even as he became an NFL reporter on CBS and now Fox.

advertisement | advertise on newsday

“People for so long couldn’t understand it, and now people have all kind of latched on,” he said. “I cornered a friend of mine in an illegal fight in like 2001 or something in Brighton Beach [Brooklyn] and here we are now on the marquee at Madison Square Garden.

“Then we were sneaking around. Now it’s in the World’s Most Famous Arena on Veterans Day weekend. It couldn’t be bigger. If you asked me way back when my dream trajectory, what it would be, I never would have said this. It would be outlandish and far-fetched.”

CBS allowed Glazer to keep fighting but Fox made him give it up when he joined the network in 2007, which he said was the right move for someone who “wasn’t exactly an elusive feller.”

“I’ve always been into combat sports, and people kind of looked at me like I was an idiot,” he said. “Back then you couldn’t tell some girl you were dating’s dad, ‘Well, I’m a cage fighter.’ ‘Excuse me, you’re a what?’ ”

Glazer has hosted a variety of MMA competitions, including Donald Trump’s Affliction, which briefly sought to take on UFC in the late 2000s.

@NewsdaySports

Jamie Horowitz, president of national networks for Fox Sports, said, “When you ask sports fans the reasons they like UFC, among the descriptive words you hear are things like ‘blunt,’ ‘fearless,’ ‘rebellious.’ That’s sort of like the ethos of UFC.

“I also think those are the same words people would use to describe Jay Glazer. And doubly good news, it’s the words people would use to describe Fox. And so I think that makes Jay a natural match for both Fox and UFC.”

Glazer will wrap up his weekend in New York with another retro moment. Hours after post-fight coverage he will appear on “Fox NFL Sunday” from a ramp outside the Garden’s atrium, where in the late 1990s he hosted an MSG show called “Unnecessary Roughness” with Curt Menefee, on which the Giants’ Michael Strahan was a frequent guest.

Twenty years later, all three work together on the Fox NFL pregame. “Crazy, right?” Glazer said.