Jeff Horn has dared Brian McIntyre to make good on his threats to physically attack his trainer Glenn Rushton as the pair prepare to cross paths for the first time.
But Horn said McIntyre should be "petrified" of Rushton, a former nightclub bouncer and experienced martial artist.
The trainer of Horn's American challenger Terence Crawford, McIntyre has launched into several foul-mouthed rants attacking Horn and Rushton in the lead-up to Sunday morning's (AEST) title fight in Las Vegas.
His grievances trace back to when Rushton called Crawford a "princess" and told him to "toughen up" after the original April date for the bout was abandoned because of a hand injury suffered by the Nebraska native in sparring.
McIntyre responded by saying the fight would be "easy work" for Crawford, warning Horn that "we f***ing you up, we f***ing your trainer up".
A bemused Horn wondered if McIntyre - who copped 14 defeats, including seven by knockout, in his 21-fight career as a professional boxer - knew what he would be getting himself into.
Rushton might be 60 years old but knows how to handle himself, having won numerous national martial arts titles and spent years on the door fending off troublemakers at Brisbane pubs and clubs.
"I'd be petrified, to be honest," Horn said.
"I wouldn't want anything to do with him. He doesn't know that yet but maybe one day he'll find out. He's devastating.
"Back in the day I can remember him doing some demonstrations, the way he just took guys down so quickly - not even hurting them, but just taking them down to the ground. I was like, 'that was fast'."
Horn and Rushton are due to come face-to-face with Crawford and McIntyre for the first time at the official pre-fight press conference early on Friday morning (AEST) - although that moment may come sooner, with the opposition camp also moving in to the same hotel, the MGM Grand.
Horn is rated as a 6-1 chance by Las Vegas bookmakers but is confident he can overcome Crawford, a former unified junior welterweight champion who is stepping up a division.
"I think he's a bit hyped up," he said.
"He's a good fighter but no-one believes in what I can do. They watch me and they're like 'he looks average, we could easily beat him.'
"I know myself I can adjust to different people in the ring."