Veteran Danny Green has brushed off criticism of the weight limit for his world title fight with Kiwi Shane Cameron, saying he's the one taking a big risk.

Cameron will dwarf him by up to 10 kilos when they clash for the vacant IBO cruiser-weight crown at Melbourne's Hisense Arena on Wednesday night.

The pair sat side by side at a Melbourne media conference on Monday, with the difference in size obvious despite Cameron shedding eight kilos to make the catch-weight of 89kg agreed on for the bout, with the usual weight for the division 90.7kg.

Cameron is a natural heavyweight and has fought at 108kg and also 106kg when he "wrestled" with former NRL player John Hopoate in 2010.

"It is a massive difference and a massive advantage," Green said of his bigger opponent.

"I expect Shane, a man of his size, to tip the scales at 96(kg) minimum by the time of the fight while I'll tip them at 86.5 maybe.

"Of course, it is a risk but it's a risky sport. It's part of the excitement."

The West Australian has been criticised for use of a "Danny Division", though it's a legal tactic which he also used when defending the belt against undefeated American BJ Flores in 2010.

He said it's something Cameron had to do to obtain a fight against a boxing "big fish".

"It's the catch-weight and it's been going on forever. Sugar Ray Leonard did it against Donny Lalonde and Tommy Hearns ... Manny Paquaio, Floyd Mayweather have all fought catch-weight," said Green.

"I'm the one putting my balls on the line fighting a heavyweight.

"I'm just trying to square the advantage that he's got as a much bigger, naturally-stronger man.

"We agreed it wouldn't happen anywhere over 89kg ... and, unfortunately, the boys are starting to carry on and whinge a bit."

While 39-year-old Green is gunning for his fourth world title, it's Cameron's initial attempt and the first by a New Zealander since David Tua fought Lennox Lewis in 2000.

Green is widely tipped to retire - for the second time - after the fight but said a decision was yet to be made.

"No Australian-born fighter's won four world titles before so that's a big motivating factor," Green said.

"I really enjoy what I do and the fact that there's a lot of interest in Australia and worldwide in the boxing community still motivates me."

Cameron said he had turned to a dietician to lose the weight, which was the most he'd had to drop.

But he was confident he had retained his power.

Cameron said if he didn't accept Green's conditions, he wouldn't have had the world title fight.

"He wanted me to lose more but we agreed on the 89kg," he said.

"I know the strength and speed is still there so I don't need to be bigger."

- AAP