(AP) -- Jon Jones has teased making an appearance at WWE's SummerSlam event to stir things up in his quest for a mega fight with Brock Lesnar.
Lesnar might have trouble keeping an eye on Jones, should the UFC star grab a seat in the front row. The WWE universal champion has a title defense against three wrestlers in a Fatal 4-Way main event Sunday night at New York's Barclays Center.
With a loss, Lesnar could have more free time to hype a potential fight vs. Jones -- the match stipulates he will leave WWE if he loses the championship.
OK, Lesnar isn't going anywhere. He's WWE's No. 1 drawing card.
But the pay-per-view provision only fueled speculation among fight fans that Lesnar could jump ship and return to UFC for a showdown against Jones. Jones called out Lesnar immediately after winning the light heavyweight championship last month. Lesnar warned Jones, "Be careful what you wish for, young man ."
Lesnar reigned as heavyweight champion in his first stint at UFC and easily became the most successful crossover fighter, from pro wrestler to mixed martial artist.
Lesnar's not the only spandexed warrior who has stepped inside the squared circle and eight sides of cage fighting.
Some notables:
-- CM Punk was a one-round flop when the former WWE champion made the move to UFC.
-- Ken Shamrock ruled as "The World's Most Dangerous Man" in the early days of UFC before he wrestled future Hollywood star The Rock at WrestleMania.
-- Bobby Lashley is trying to master both worlds, currently competing as a heavyweight for both Bellator and Global Force Wrestling.
-- Ronda Rousey stood side-by-side with The Rock at WrestleMania and was recently spotted at a WWE-backed women's wrestling tournament . Could the one-time face of UFC find herself competing in the faux fighting world of WWE?
-- WWE star Becky Lynch and UFC champion Cristiane "Cyborg" Justino had a social media "feud" to push a potential SummerSlam bout.
-- Dan "The Beast" Severn, Tank Abbott, Rampage Jackson and Dave Batista have all had mixed success trying to mesh triangle chokes and ankle locks with dropkicks and piledrivers.
Shamrock was a key cog in UFC's formative years, fighting to a 36-minute draw at UFC 5 on April 7, 1995, and made the jump during WWE's zenith in "The Attitude Era."
"It's difficult to go from a career where you're kicking tail and going out and dominating people and then all of a sudden you have people telling you, you're going to lay down in this fight," he said. "That was the most difficult part for most athletes crossing over. You have to put yourself in a vulnerable situation and make people think you're hurt. We were so programmed in our pride to not let people know you're hurt."
Shamrock at times found the scripted outcomes almost as tough to swallow as the dog food "The British Bulldog" Davey Boy Smith shoved in his mouth at SummerSlam in 1997.
In the `90s, UFC had yet to gain the mainstream credibility the sport has today and Shamrock entered a sports entertainment world where he knew none of the wrestlers legitimately wanted to mess with him. But they were curious if Shamrock could change from martial artist master to entertainer -- and he did. Shamrock kept many of the traits that made him a star in UFC -- in the WWE he was known for suffering "internal bleeding" rather than quitting.
"I was a world champion. There was nobody in the world that could beat me," Shamrock said. "When I first went there, there were a lot of people that were very upset that I would go there and do something like that. But if it wasn't for the fact that I crossed over, we might not be talking about the UFC or the WWE as we talk about them now."
The 41-year-old Lashley is perhaps best known for representing Donald Trump in a "Battle of the Billionaires" match at WrestleMania in 2007. Lashley has wrestled for Global Force Wrestling since 2009, right around the time he got serious about chasing an MMA career. He's won all five bouts since he joined Bellator in 2014 and has stated his desire to fight for the heavyweight championship .
"You can't just say, OK, I fought before so I want to be a professional wrestler," Lashley said.
Lashley is involved in a GWF storyline where he threatened to quit the wrestling promotion to become a full-time MMA fighter.
"He needs to focus on which one he can make the most money on and the biggest splash in right now and in my opinion, that's MMA," American Top Team trainer Dan Lambert said.
Rousey made millions under contract at UFC and can make a bigger splash now working for WWE. Rousey, one of the more celebrated athletes in the world, has kept a low profile since her unbeaten streak came to a thud with two straight losses that put her UFC career in doubt. She's coaching D-list celebrities on "Battle of the Network Stars" and was a guest of WWE executive Triple H at a taping last month of the Mae Young Classic.
"Ronda Rousey for me is a WrestleMania attraction," veteran WWE announcer Jim Ross said. "I think she's a big enough star to wrestle perhaps Charlotte, or whomever. There's a lot of ways to market Ronda Rousey. I think her love of the wrestling business and the sizzle that comes with it for WWE is something she's very interested in. I don't think it's a payday issue as much as it's a new adventure."
