The $1 million debt that got Sonny Bill Williams into boxing

Sonny Bill Williams is back in the ring this month. Photo / Photosport

Sonny Bill Williams admits he wasn't a natural boxer and only got into the sport because of significant financial debt.

The cross-code superstar, who will fight AFL champion Barry Hall in Sydney on March 23, says he found himself in $1 million debt after leaving the Bulldogs in the NRL to play rugby in France in 2008.

He says it was good friend and trainer Anthony Mundine's idea for him to step into the ring, leading to his first boxing fight against Gary Gurr on the undercard of Mundine's bout in 2009.

"I couldn't throw a punch," Williams told Wide World of Sports.

"When I took off from the Bulldogs I was in $1 million debt. So I had a few financial struggles in France for a few years. When I came back Choc (Mundine) and (manager) Khoder Nasser thought it would be a great idea to jump on the card just to knock off a little bit of that debt that I owed them. Hence the reason I got in the ring [against Gurr].

"So when we were in France, he (Mundine) got me to shape up and throw a punch but, besides a few fights growing up, I wasn't that aggressive style that I played with on the footy field. I never went in the boxing gym and learned how to throw a proper jab or straight right so that's why it's pretty funny to see where I'm at now."

Sonny Bill Williams during his first boxing fight against Gary Gurr in 2009. Photo / Photosport

Williams, now 36, has come a long way since then and has amassed a perfect 8-0 record in the ring, including victories over legitimate professionals.

Aside from having Mundine in his corner for his next bout, Williams has also been training with some big boxing names, including Kiwi stars Joseph Parker and David Nyika and world heavyweight champion Tyson Fury.

"We did some body sparring, quite a bit of body sparring actually," Williams told SEN of training with Fury during a six-week camp in the UK.

"To be honest, he (Fury) is a gentleman, he's a really, really good guy.

"He welcomed me in because he knows I'm close with Joseph Parker, he just welcomed me in like I was one of his close mates.

"I was in the inner sanctum and got to train alongside him and got to run."

It’s been a privilege to see first hand how much of a gentleman @Tyson_Fury is & why he is the best heavyweight in the world. Also seeing my brother @joeboxerparker work his way back to the top has been inspiring. @DavidNyika Your time is coming you beast ✊🏽 #EffemupFridays pic.twitter.com/v7aIb2d2NO

— Sonny Bill Williams (@SonnyBWilliams) January 21, 2022

Mundine says Williams' progress in the boxing ring is "a credit to his hard work and belief and commitment to the sport".

"When he fights Barry, they're going to be calling him Sonny Bill Mundine," Mundine told Wide World of Sports.

"He's learnt bits from everybody and he's going to mould his own sort of style.

"Watch him shadow box now – he looks like a fighter, so professional."