SAN JOSE, Calif. -- Cain Velasquez leans up against the ring ropes in a small pro wrestling gym wearing a maroon Arizona State workout top. It's his third shirt of the practice. The other two were sweated through.

The former UFC heavyweight champion is a month into training in lucha libre at the Pro Wrestling Revolution Training Academy. Three or four times a week, with some sessions going up to five hours, Velasquez is getting a crash course in a different form of wrestling than the one he is known for.

Velasquez is throwing clotheslines, slamming workout partners and going through drills in preparation for his pro wrestling debut at AAA's Triplemania on Aug. 3 in Mexico City. One of the baddest men on the planet will be donning a mask and performing in a tag team match in Mexican lucha libre's version of WrestleMania.

Cain Velasquez has spent the weeks leading up to his professional wrestling debut with AAA training at the Pro Wrestling Revolution school in Las Vegas. Marc Raimondi/ESPN

By all appearances, he's putting in a lot of work and having a lot of fun learning his new craft.

"I've always loved lucha libre growing up, watching it as a kid with my parents," Velasquez told ESPN. "We'd go to Mexico and get the toys, the masks, the ring that was handmade out of wood. Wrestling was a big part of my culture growing up."

Velasquez, 37, has wanted to cross over into pro wrestling for some time. He really caught the bug when he attended WWE's Elimination Chamber event in February 2018 with teammate Daniel Cormier, the reigning UFC heavyweight champion, and other UFC fighters. Ronda Rousey was "signing" her WWE contract on the show, and the experience brought Velasquez, who also had his wife and two children with him, back to his childhood.

"Cain doing professional wrestling is insane to me," Cormier said. "I love it so much for him. We went to an event last year and I saw Cain really take in the environment and let himself really enjoy the wrestling. And to get to do it in Mexico City, I know how much that means to him."

In July 2018, during an injury layoff from the UFC, Velasquez spent a few days at WWE's Performance Center in Orlando, Florida. The trip gave Velasquez the opportunity to evaluate whether he could take to the physically demanding world of pro wrestling. Velasquez went through workouts and drills, and even jumped off the top rope. Velasquez said he got rave reviews, and at that moment he knew for sure pro wrestling was something he wanted to do.

From that point on, it was just a matter of making it happen logistically. When Velasquez signed a new contract with the UFC late last year, he made sure it allowed him to perform as a pro wrestler; his old deal had a clause that forbid it.

One of the chief concerns at this point for Velasquez is his health, as his MMA career has been plagued by injuries to his back, knees and shoulders in recent years. He has fought only three times since 2013. In 2016, he was pulled from a UFC heavyweight title fight against Fabricio Werdum for medical reasons by the Nevada State Athletic Commission (NSAC).

Velasquez returned to the UFC in February after more than two years away and fell to Francis Ngannou via first-round knockout. The plan was for Velasquez to venture into pro wrestling shortly after that bout, but he injured his left knee against Ngannou. Velasquez says he tore his PCL and MCL in the fight, but held off on surgery in favor of rest and rehab. After exploring the possibility of pro wrestling, Velasquez is confident he'll be able to perform without adding further injury.

In March, Velasquez appeared at a news conference where he announced that he had signed with AAA -- one of Mexico's two biggest pro wrestling promotions.

IN LUCHA TRAINING, Velasquez wears a large plastic brace on his left knee. He says it's more of a precaution, and the knee feels strong.

"Right after the [Ngannou] fight, I felt how bad it was then," Velasquez said. "I was like, holy s---. It was hard to put my leg in certain ways. [Then] it started coming [back], it started getting better."

As he runs the ropes and moves around the ring, Velasquez doesn't favor the leg at all; he's able to lift training partners who weigh more than 300 pounds with ease. With AAA planning a U.S. expansion in the fall, including shows at Madison Square Garden in New York and The Forum in Los Angeles, Velasquez wants to be ready to have a match on both cards.

While lucha libre will be Velasquez's focus for the next few months, he's not done with MMA. Velasquez said he plans on continuing with the UFC and wouldn't rule out a return to fighting before the close of 2019. For now, he's working with other fighters at American Kickboxing Academy, in between his wrestling training sessions.

That's not to say that lucha libre is a temporary move, though. Velasquez sees it as a parallel career with MMA, in fact, and potentially something he could do for a long time after his fighting career is done. That's how seriously he's taking his training.

"This could be the future for me," Velasquez said. "Anything I can do, I try to be the best at it. I'm very competitive in that way. I'll bust my ass to get every move down and also to sell every move. ... I want to be a black belt in lucha, if they gave out belts. That's my goal -- to be the best luchador that I can be."

MMA fighters moving into pro wrestling, and vice versa, is nothing new. UFC Hall of Famer Ken Shamrock was a longtime pro wrestler in WWE and Japan. More recently, one of the UFC 's biggest stars, Ronda Rousey, left the promotion and had a major run in WWE. Brock Lesnar, who Velasquez defeated to win his first UFC heavyweight championship in 2010, is the current WWE Universal champion.

Cain Velazquez arrives in Mexico City with his family ahead of his first professional wrestling match. Alejandro Cegarra for ESPN

"Cain is a phenomenal athlete and I believe he will do fantastic," Cormier said. "He has [dived] headfirst into learning how to wrestle. He has never cheated anything in his life and that's the approach he has taken to learning professional wrestling. He's full go. I am so excited for him."

MMA and pro wrestling have plenty of similarities in terms of valuable tools, including the kind of amateur wrestling and mixed martial arts background that made Velasquez a great college wrestler and a UFC champion. Combat sports have long embraced the type of over-the-top promotion that traces back to the foundation of pro wrestling, like when Muhammad Ali was inspired by Gorgeous George in the 1960s.

Interesting enough, though, Velasquez has never been that kind of fight promoter. He has almost never spoken negatively about an opponent, even when he's building up a fight.

"I have a different mentality in MMA," Velasquez said. "It's no playing, it's f---ing down to business. That's why I've never done that."

Yes, Velasquez is an incredible athlete, but his mentality is what makes Vinnie Massaro, a veteran of the Lucha Underground television show who has been training wrestlers for 15 years, believe he could be "one of the best pro wrestlers in the world." Massaro said Velasquez is not just there to learn a few cool moves and be on his way. He wants to learn pro wrestling psychology, the reason why performers do things in the ring.

"He loves pro wrestling, which means he wants to learn about pro wrestling and lucha libre," Massaro said. "I can get any MMA guy into pro wrestling, but if he doesn't want to learn it's impossible. It's a waste of time ... The main reason why I think he can be so great is because he's very good with constructive criticism and he's very good with learning new things and being able to adapt to them."

Velasquez says MMA and pro wrestling differ in a few key ways. In MMA, Velasquez is famous for his speed, pressuring style, oppressive wrestling and cardio. He has the most takedowns in UFC heavyweight history (34) and is tied for the most knockout wins (10) with Junior dos Santos and Derrick Lewis.

"In the UFC, you throw combos," Velasquez said. "You pretty much try to be as offensive as you can, smother them, not give them any space. Just f--- them up. And [pro wrestling] is like, you do a move, you celebrate. It's like in football. You do a move, you celebrate it -- 'f--- yeah!' You go back in, you do a move, you celebrate it. Every move has a great significance out there."

Cain Velasquez has only fought twice in the UFC since losing the UFC heavyweight championship in June 2015, but he's intent on returning to the Octagon as soon as late 2019. In the short-term, he intends to pursue MMA and lucha libre in tandem. Joe Amon for ESPN

Velasquez will be entering the ring at Mexico City Arena in front of more than 10,000 people in just a few days, and he doesn't have time as a luxury. Massaro said he's mainly focusing on training Velasquez for his debut -- a six-man tag team bout in which Velasquez will team with Psycho Clown and Cody Rhodes to take on Texano Jr., Black Taurus and a mystery partner.

Velasquez invited Psycho Clown to San Jose to train with him, and he has been in touch with Rhodes. Over the past month, video of Velasquez's training sessions has been sent to legendary luchador Konnan, a backstage official with AAA who will help explain how the match will play out.

While the physical side of preparations are going well, Velasquez has to work a little harder on the character side of pro wrestling. But he's getting strong guidance there, too, from Massaro.

More than anything, he wants Velasquez to be himself "times 100."

"I'm not saying go out there and be Conor McGregor and showboat, because that's not like him," said Massaro. "I don't want anything forced, because people will be able to see it. I just want him to be himself."

COULD VELASQUEZ, THE first Mexican American combat sports heavyweight champion, be the next big thing in lucha? While wrestling is still very popular in Mexico today, led by AAA and rival company CMLL, there aren't any big, mainstream stars at the level of an El Santo or Blue Demon.

El Santo, a legendary luchador from the 1940s and 1950s, is one of the most recognizable and iconic figures in the country's sporting history. He starred in more than 50 movies in his mask and full luchador outfit, and was so impactful that he was inducted into WWE's Hall of Fame in 2018 for his contribution to pro wrestling. Blue Demon was his chief rival, a villain (or rudo) who later turned good (or técnico).

With Velasquez's popularity and status among Mexican fans, he has the potential to fill that void.

Upon his arrival in Mexico City in the week leading up to his match at TripleMania, Cain Velasquez was swarmed by fans and local media at the airport. Alejandro Cegarra for ESPN

"They appreciate a performer," said filmmaker Ian Markiewicz, who directed and edited the 2016 documentary "Lucha Mexico." "If he goes out there and gives a real show and he really goes and does it, I think he could be a major draw. Sometimes when people come out of the UFC or something else, they don't fully get there's a performative aspect of wrestling that's incredibly important to whether or not fans are going to like you."

Professional wrestling spread from the United States to Mexico in the late 19th century and really started taking off in the 1930s. Lucha libre has grown to be a staple of Mexican culture.

"These people were doing something kind of extraordinary and it was entertainment," Markiewicz said. "I think they took to it, at least how I always perceived it, as these are our local guys, but they're more than that. These are our heroes. They were the Batman and Superman -- El Santo and Blue Demon, that's who they were to them."

WWE in the United States is a multibillion-dollar company with a huge social media reach and lucrative television deals in every corner of the globe. But Markiewicz said pro wrestling hasn't "permeated the culture" in the U.S. the way lucha has in Mexico.

"When you're there in Mexico, the lucha mask is this icon that they have everywhere," Markiewicz said. "It doesn't matter where you go. You go into [stores], you see birthday cakes with lucha libre on them. You go to any sporting event, it doesn't matter what it is, there are still going to be people with lucha masks."

Velasquez lists El Santo, his son El Hijo del Santo, Blue Demon and Mil Mascaras among his childhood heroes. Another luchador that really left his mark with Velasquez was Octagón, who had a legitimate black belt in karate and threw impressive strikes.

That connection to his youth and heritage is one of the major reasons Velasquez, who was born in the United States to Mexican immigrant parents, says he ultimately ended up with AAA. While he says he would also have been allowed to perform for WWE under his UFC contract, Velasquez felt a connection to lucha libre's "more acrobatic" style, which was what he grew up watching and enjoyed.

Presentation is also very important in lucha libre. While he's coy about exactly what he'll wear in the ring, Velasquez says he will don a new, unique mask for Triplemania -- like a traditional luchador -- but he's not sure if he'll take it off before he wrestles. He's keeping the look of the rest of his gear a secret.

"It's gonna be something that's very familiar to people, but also something that's new," Velasquez said. "Something familiar like, I go out and fight, this is what I wear. But also something a little new to kind of incorporate a little bit of luchador and MMA together."

It's hard to say how continuing his MMA career and his new lucha libre dreams will play out in tandem over the years to come, but everything Velasquez has done to this point seems to prove that he's in it for the long haul.

"I'm gonna do more [pro wrestling]," Velasquez said. "I just want to keep getting better at it. I feel like I have so much potential with this. Now that I've been doing it and I know how much I can learn and how better everything can be, yeah man, it's fun. F--- yeah, I want to keep doing it."

Additional reporting by Eric Gomez.