The two premiership-winning NRL greats will square off in a five-round heavyweight blockbuster in Sydney on November 6 after Gallen answered an SOS call from No Limit Boxing to take on the former Melbourne Storm giant.
Now 45, Gallen never wanted to fight again, 16 months after beating fellow league legend Sonny Bill Williams, but now he wants retribution after claiming Asofa-Solomona broke the mateship code and landed too many verbal low blows.
"I rang No Limit for him. Well, not for him, but I did ring them and say he wants to get involved in boxing," Gallen told AAP on Tuesday.
"So for him to then sign with them and to be calling me out after every fight he's had, it's just not a bloke thing to do. I don't think it's the right thing to do.
"I told him I was done. I told him I was finished. He had all that intimate knowledge and now he can't stop calling me out. I'm going to smash his face in."
Gallen initially turned down a million-dollar offer to slug it out with "The Big Nasty" but finally relented after promoters threw even more cash at him after struggling to find match-ups for the two-metre-tall behemoth.
As well as being 15 years older than Asofa-Solomona, Gallen will be conceding 20cm in height to Asofa-Solomona.
But after taking down the taller Williams, a one-time WBA heavyweight world champion, in his most recent fight in July last year, the former NSW State of Origin series-winning skipper does not fear Big Nelson one iota.
In fact Gallen, who has already banked some $25 million from 16 wins as No Limit's long-time poster boy, thinks the ex-Kiwi Test enforcer is a s*** boxer who has no future in the sport.
Asofa-Solomona has a nine-fight, multi-year-deal with No Limit and proved a class above in his first three professional bouts against fellow ex-NRL forwards Jeremy Latimore, Jarrod Wallace and George Burgess.
"After his second fight when he called me out, I was like, 'mate, stand on your own two feet. Be a man. Make your own way in boxing, stop using my name to'," Gallen said.
"He wasn't calling out Curtis Scott. He's not calling out Junior Paulo. They're footy players. They're younger. I'm 45. He keeps bringing up my name after the fact because he knows I didn't want to do this anymore.
"I'm just really disappointed in that. It's just not brave. He's a f***ing rat for it and he's lit a fire in me that's made me want to come back and I get to try and do something about it."
