A who's who of the Sydney sporting world, led by NRL super-coach Wayne Bennett, former rugby league teammates and rivals Laurie Daley, Matthew Johns and Gorden Tallis, and AFL great Michael O'Loughlin gathered at Circular Quay to pay tribute to Mundine.

Eleven-times world surfing champion Kelly Slater even phoned in, while Australian cricket coach Justin Langer was among those to send video messages to the triple world boxing champion and rugby league premiership winner.

Revered for his sporting prowess and derided in equal measures for his motor-mouth and self-promotion, Mundine is a generous and gentle soul to those who know him best.

Tallis recalled the touching story of how Mundine rushed, unannounced, to Tallis's sister Jannita's death bed in Queensland before cancer took her life in 2009.

"That's the side I see. That is the Anthony Mundine that I know," Tallis told AAP.

"The Anthony Mundine the public sees, I don't know that bloke. It's there to get publicity and to sell fights and he's certainly done that.

"He sold them all on his own.

"But everybody's here because of the person he is, not because of his sporting career.

"He actually flew from Sydney to go see my sister (before she died) so that's the person we all know away from the sport.

"I just wish Australia saw him the way his mates see him.

"He's a great fella and in the toughest times he'll always have your back."

In retirement, Mundine will continue being an Indigenous leader, providing employment pathways for his people through his business.

The 45-year-old will also help Indigenous youth with their mental health.

Daley believes Mundine's legacy will extend well beyond his sporting achievements.

"What a wonderful human being he is," Daley said.

"We all admire what he does in the boxing ring and on the rugby league field, but it goes much deeper than that.

"Choc's been a wonderful ambassador for the Indigenous community. He sticks up for his people, he's very passionate about what he does.

"Someone that stands up for his own convictions and what he believes in.

"He is without doubt one of Australia's greatest ever sportsmen but, while he's had a wonderful career in rugby league and in the ring, I think we're about to see the start of a bigger legacy."

Budding boxing superstar Tim Tszyu said Mundine was a hero to him who revitalised the sport in Australia following his famous father Kostya's retirement in 2005.

"He's done great for Aussie boxing. It had a bit of a pause and stop after my dad's career and he brought it back," Tszyu told AAP.

"Everyone was in pubs and watching the fights, so he brought it back.

"He had some great fights in Australia. A hundred per cent big respect for him."

Johns said Mundine's rugby league feats - including a 6-0 winning record over Daley and Brad Fittler when going head-to-head with the two greats as a five-eighth - also should not be forgotten.

"Choc was such a wonderful player and such a difficult guy to come up against," Johns said.

"I remember one day playing at Kogarah, he beat me twice with his beautiful left-foot step and the second time he walked past me, he said: 'Give it away, old man' and I was actually 24."

O'Loughlin said Mundine had even left his mark on the AFL.

"I met Anthony when I was about 18 or 19 years old and he actually thought he could help the Swans win a premiership in front of Paul Kelly and Tony Lockett," the Swans legend said.

"I know his dad (Tony) really well. His dad's a legend down in South Australia and when I go back home, all my crew and all my community, they always say: 'What's Tony Lockett like and what's Paul Kelly like and what's Choc Mundine like?'

"That's your reach, brother. He's one of those guys who'll give you the shirt of his back and his last dollar.

"He's got so much respect in the AFL world and I'm glad I got to witness it first hand."

"The Man" himself said winning the 1997 Super League title under Bennett with what Mundine hailed the "best team of all time" and claiming his first world boxing title with victory over "gangster" American Antwun Echols in 2003, were the two biggest highlights of his career.

"I just knew from a young age I was going to be a (boxing) champion," Mundine said.

"Football was my passion and my love but I knew one day I would leave and pursue my other dream."

The 45-year-old's next dream is to continue "bridging the gap" for Australia's Indigenous community.

"We've still got a lot of work to do. Racism is pretty rife and always will be," Mundine said.

"It's like a blazing fire and all we can do is pour water on it and limit it as much as we can."

Australian Associated Press