Nelson Asofa-Solomona is pledging to knock Jarrod Wallace's lights out after copping a loose verbal low blow from his heavyweight former NRL rival.

The two ex-front rowers will square off on the undercard to Tim Tszyu's all-or-nothing super-welterweight showdown with Albanian brawler Denis Nurja in Wollongong on Sunday.

After turning his back on rugby league to pursue a boxing career, Asofa-Solomona KO'ed fellow ex-NRL star Jeremy Latimore in the opening round of an explosive debut in January. 

Wallace, though, believes he will have the former Melbourne Storm giant's number on his own pro debut at WIN Stadium.

'He's big, he's powerful, I've got respect for him,' Wallace said on Thursday.

'But there's plenty of flaws, you know. Craig Bellamy's seen it. That's why they sacked him.

'So it's time for me to come in and fight in boxing now. I'm excited for the fight. It's going to be fun and we're going to go at it.'

Big Nelson reckons it won't be much fun at all for Wallace.

'He needs to promote the fight. He needs to get eyes on the 5th of April, but I guarantee it's going to be a highlight-reel finish for me,' Asofa-Solomona said.

'I'm going to put on a show.'

The trash-talking Wallace isn't convinced.

'Look, he had an impressive fight against 'Lassie', don't get me wrong, but Lassie's not a fighter. He's a lover, that fella,' the former Brisbane Broncos, Titans and Dolphins star said.

'So we take him into deep water. Everyone wants to see. I'm keen for it, so don't discount me a bit. I've been training hard.'

With bigger fish to fry in his multi-fight No Limit Boxing contract, Asofa-Solomona is having none of it from the six-time Queensland State of Origin rep.

'It's going to be a demolition job and it's going to be even more devastating (than Latimore),' said the former New Zealand Test star.

'I think he's just trying to talk himself into it. He's pretty confident with his game plan.

'But, like Mike Tyson said, everyone's got a game plan until they get punched in the face and I really feel once he feels those 10-ounce gloves, he's going to feel a shock as well.'