Any NRL players considering a career in boxing will likely have their interest piqued by former Cronulla Sharks captain and renowned pugilist Paul Gallen's revelation about how much money he has earned during the last three years of his career in the ring.

Ahead of his final fight against former Brisbane Broncos player Justin Hodges, Gallen has revealed the huge sums he's earned as he tries to entice Sonny Bill Williams to replace him as Australian boxing's new pay-per-view headliner.

With Williams' boxing future currently undecided, Gallen was clearly trying to offer an incentive.

โ€œThere's definitely plenty of money to be made,โ€ Gallen said, per Fox Sports.

โ€œI just don't know if Sonny wants to do it. I've been told recently by a lot of people that he doesn't actually like fighting much.

โ€œYou'd have to ask him. But if I were Sonny, I wouldn't be stopping.โ€

Gallen denied suggestions that age may be a concern for the former NRL and All Blacks star, having retired from the NRL at 37 and making a successful career for himself.

โ€œThe guy is 37 โ€“ and look what happened with me from roughly the same age,โ€ Gallen said.

โ€œI've grossed $25 million from the past three years. That's a lot of money.

โ€œAnthony Mundine grossed $75 million over almost 15 years.

โ€œI wouldn't be leaving if I were Sonny.โ€

NRL Rd 19 - Roosters v Sharks
SYDNEY, AUSTRALIA - SEPTEMBER 19: Sonny Bill Williams of the Roosters reacts during the round 19 NRL match between the Sydney Roosters and the Cronulla Sharks at Sydney Cricket Ground on September 19, 2020 in Sydney, Australia. (Photo by Mark Metcalfe/Getty Images)

Despite the words of advice, Gallen denied that he was ever likely to become close friends with โ€˜SBW'.

โ€œSome people just don't mixโ€ฆ but I'm still not going to talk s**t about him.

โ€œAs I've said, I think he should keep fighting. As for who though? No idea.

โ€œWhen you break down his record it isn't good, but if there are big enough fights I'd be taking them.โ€

Last year, Williams revealed that he originally took up boxing after he found himself in $1 million debt after quitting the Canterbury Bulldogs. He told the UK Mirror he was aided by Mundine, who put him on an undercard to help his friend financially.

Since then, Williams has developed a passion for the sport, claiming it 'lit a fire' inside him.

"I'm really focused on it [boxing], and now before I walk off into the sunset, I want to give boxing a good crack because I've only done it for six or eight weeks and I've seen the improvement that I've had in that time. So I just want to see where I'm at in 24 months," he concluded.