CHICAGO — My how things have changed over the last few years.

CM Punk, the former WWE champion and top star, is now a UFC fighter. Meanwhile, Ronda Rousey, she of the dominant UFC run and title reign, is now in WWE.

The two have been friends for a long time, dating back to when they were each competing and performing in their previous mediums, and they have kept in touch. On Wednesday at UFC 225 workouts here at Chicago Theatre, CM Punk said he spoke with Rousey before she made her WWE in-ring debut at WrestleMania in April.

“The only thing I told her was to just have fun,” said Punk, who fights Mike Jackson in his second UFC fight Saturday. “I don’t know what it’s like back there in this current environment. I know she’d probably get treated differently, just as I know I probably get treated differently here. The only thing I ever told her is, ‘I know you’ve got a lot of people telling you, do this, don’t do this’ — whatever you do, when you go out there for WrestleMania, make sure you have fun. Period.”

CM Punk, 39, did not leave WWE on good terms. He took an absence from the promotion in 2014 and was fired a few months later. He’s been embroiled in a defamation lawsuit with WWE doctor Chris Amann, which culminated with a Punk victory Tuesday, just one day before the beginning of fight week.

Likely due much to that, Punk said he did not watch Rousey’s WrestleMania match, where she teamed with Kurt Angle against Triple H and Stephanie McMahon.

“No, I did not,” CM Punk said. “I saw a couple of clips here and there. And still, when I say it’s hard for me to watch wrestling, it’s not like an anxiety thing, it’s not like an, ‘ugh, I can’t do it.’ I literally, I can’t get through eight seconds without being like, ‘OK, umm, can I change the channel? I’m bored, I gotta watch something else.’ It’s like going to a baseball game at [New York Mets stadium] CitiField. I like Wrigley Field, it’s old school. Going to a baseball game at CitiField, it’s like a guy gets ball four and they blow off fireworks and there’s LED screens on everything.

“Wrestling now is completely like that. There’s LED screens everywhere and there’s flashing lights and I feel like I’m gonna have a seizure.”

Punk said it’s not much different outside the WWE, either. The way pro wrestling is now, he said, just isn’t his taste.

“Same thing,” Punk said. “I don’t know why. Subconsciously, there’s like a disconnect. I see clips. I know [New Japan star] Kenny Omega is the hot guy. He’s probably one of the better guys in the world right now, but it’s the same thing. I’ll watch clips of matches, I don’t see myself watching a full match. I just can’t do it.”

When Punk was coming up, he said he preferred the small shows in small, intimate venues — ones that were not on television and didn’t have any of the glitz and glamour.

“I think it’s definitely too glossy, but it’s been like that for a long time,” CM Punk said. “My jam was house shows before they started calling them live events, where it was a curtain and a ring and a light above the ring. That was my jam. That was my world, that was where I liked to thrive.”