Mundine, who drove Williams to the airport on Saturday for his shock departure from the Bulldogs and the NRL, spoke out at the weigh-in for the fight - his first since relinquishing his WBA super-middleweight title to move to the hotly contested middleweight division - in support of the Kiwi star he described as a "brother".

Mundine was one of Williams's few confidantes before the second-rower flew out for a $3 million, two-year deal with French rugby union club Toulon, but he denied the issue had been a disruption to his pre-fight preparations. "Nah, no distraction, man," Mundine said. "I take it all as a positive. I never take anything as a negative, out of any situation."

Mundine provided a passionate endorsement of Williams's decision to walk out on the Bulldogs, a near-replay of his own sudden retirement from St George Illawarra in 2000 to launch a professional boxing career.

"I'm 100 per cent behind my brother and 100 per cent in his corner," Mundine said. "What he wants to achieve and what we wants to do as far as his new goals and new dreams in life … a man can change his mind from time to time. If he wants new goals and new dreams, he'll inspire kids to chase their goals and dreams, and everybody should support him."

Mundine said there were a "lot of haters out there" and criticised some people in the media as "nothing but leeches and parasites as far as writing the negative stuff about Sonny Bill Williams."

He also pointed out that Gallop, who has warned of severe sanctions if Williams breaks his contract with the Bulldogs, was formerly Super League's legal adviser, and said "in them days there were heaps of contracts broken".

Asked about the revelation in yesterday's Herald that Williams had spoken to lawyers about challenging the salary cap if the NRL succeeded in court action to prevent him from switching codes, Mundine said the ceiling on payments was an unfair restriction on a player's capacity to earn.

"There's no salary cap on workers, for a plumber or a carpenter or a builder," he said. 'A worker should get what he's worth. There should be no salary cap. There should be private ownership and they [the players] should get what they're worth. The game is making millions, tens of millions of dollars, off their names. Where is the loyalty from the NRL to the players? There is no loyalty."