The first simultaneous two-division titlist in the Ultimate Fighting Championship, Conor McGregor is looking to make more history in his combat sports career, and is taking his skills to the boxing ring in order to prove it.

McGregor will take on former multi-time world champion boxer Floyd Mayweather Jr. in a boxing match at T-Mobile Arena in Las Vegas, Nevada on August 26, 2017.

During the first stop on the four-day, four-city, three-country, two-continent tour, McGregor and Floyd Mayweather Sr. had a memorable exchange during a press conference. And the UFC lightweight champion did not mince words when it came to his professional boxing debut.

“Your boy’s in trouble, Senior,” McGregor said. “Your boy’s in trouble. Listen, he’s too small. He’s too small. I’m just telling you he’s too small. He’s too frail, his little legs, little core, small head. I’m just telling you the truth. He’s too small, Senior.

“You’ve made a big mistake. You got greedy, and that’s it. You got greedy. He could’ve been 49-0, rode off into the sunset. Trust me. He got greedy here. That was a big mistake. You mis-advised him. You should’ve kept him retired. It’s your fault.”

Including the win over Eddie Alvarez in the UFC’s New York City debut at Madison Square Garden last November, McGregor successfully fought in three weight classes over an 11-month period, posting a 3-1 record in four bouts at featherweight (145 pounds), welterweight (170) and lightweight (155).

Although McGregor has never boxed professionally, he is 21-3 in his professional MMA career, and has won nine of his 10 bouts in the UFC.

“Your boy is going to sleep, and he’s going to look so good in his sleep,” McGregor said. “I know he is. That boy is going to look good asleep. I tell you what though, he’s going to wake up a better man. He’s going to wake up a better man, I promise you that. He’s going to wake up a better man.

“You’re a fan, Floyd Sr., I know it. You’re a fan. You’re a fan. I can see it in your eyes. You’re a fan of my (stuff). I know it. I know a fan when I (freaking) see one. You’re a fan. Someone send him a signed autograph.”

During his illustrious career, the 5-foot-8, 151-pound Mayweather won the WBC super featherweight, lightweight, welterweight and light middleweight crowns, along with the IBF welterweight title, WBA (Super) light middleweight and (Super) welterweight titles and WBO welterweight championship.

On his way to the 49-0 record, Mayweather defeated Manny Pacquiao, Canelo Alvarez, Miguel Cotto, “Sugar” Shane Mosley, Juan Manuel Marquez, Marcos Maidana (twice), Arturo Gatti, Ricky Hatton and Oscar De La Hoya, all of whom are current or were former champions across several weight classes.

But that means little to McGregor, not when there is so much at stake in a boxer-vs-mixed martial artist bout.

“That was a good back-and-forth, I think,” McGregor said. “We were just going at it. It’s all noise at the end of the day.

“It’s all just noise at the end of the day. The fight is the fight. We’re going to get in, and we’re going to fight, so I look forward to it.”