The “round zero” of the impending Sandy Ryan-Mikaela Mayer welterweight clash became a territorial dispute of sorts during their press conference today.

“We do know each other from the amateur days. She said she respected me. Then you would think I’d get some type of... ‘Hey, Mikaela, guess what? I'm coming to train in America, at your gym, with your coaches and your team. Like, aren't you excited?',” said Mayer, before accusing Ryan of invading her own space.

“None of that happened. So, obviously, in my mind, she knew she was doing something a little bit shady. She knew there was going to be some problems with that. And she knew I was at welterweight. It was no secret that I was at welterweight. I was slowly moving up over the year."

Ryan (7-1-1, 3 KOs), who will be attempting to defend her WBO welterweight world title against Mayer (19-2, 5 KOs) this Friday, Sept. 27 at The Theater at Madison Square Garden, had to fight back from a crouch.

Sandy Ryan (left) and Mikaela Mayer (right) engage in a war of words ahead of their welterweight title clash - Photo by Mikey Williams/Top Rank

“We've known each other since amateur days,” said Ryan,currently rated at No. 2 at welterweight by The Ring. ““The first time I came over to America was for the Jessica McCaskill fight, and Mikaela was not at 147 then. I was on the Great Britain team, she was on the USA team, and we used to do training camps and spar. I've always respected her as a fighter, and I've always said that. I don't respect her as a person now with how she's been leading up to this fight."

Mayer, who was the Ring inaugural junior lightweight champion andis now rated at No. 3 at 147 pounds by The Ring,now sees Ryan’s invasion of her gym and her team as an advantage.

“This was all really a blessing in disguise. Like, I should thank Sandy, honestly, because I had to reroute everything, and I feel like I'm in a better position for it. I have Kofi Jantuah in my corner, who I'm extremely happy with. And they say you can't learn so much at this stage in your career, but that's not true for me. I always feel like I'm growing and getting better. We put in some good months together, so I'm excited to go out there and show that.”

Ryan doubled down on her claim of innocence.

“I never came over here to trouble Mikaela. I came over here to better my own career. You see a lot of fighters—top-end fighters, UK fighters—come over to America because the training is great here. The sparring is great. The trainers are great. You see fighters doing that to better their career, and that's exactly what I did.“

In the 10-round junior middleweight co-feature of the Ryan-Mayer main event, Puerto Rican sensation Xander Zayas (19-0, 12 KOs) will face Mexican contender Damian Sosa (25-2, 12 KOs).

Brooklyn-born featherweight Bruce “Shu Shu” Carrington (12-0, 8 KOs) will open the ESPN-televised tripleheader in a 10-round tilt against Sulaiman Segawa (17-4-1, 6 KOs).

Ryan-Mayer, Zayas-Sosa, and Carrington-Segawa will be broadcast LIVE on ESPN, ESPN Deportes and ESPN+ at 10:30 p.m. ET/7:30 p.m. PT.

The ESPN+-streamed undercard begins at 6:30 p.m. ET/3:30 p.m. PT and includes the MSG debut of Vito Mielnicki Jr. (19-1, 12 KOs), who will fight Italy's Khalil El Harraz (16-5-1, 2 KOs) in a 10-round junior middleweight battle.