By Darren Walton
He accepts the NRL may not like it, but Sonny Bill Williams says players switching codes and dabbling in boxing are realities of modern-day sport that make football careers even more enticing.
Having waltzed straight back into the All Blacks ranks after completing his second stint in the NRL in September, Williams will squeeze his seventh professional boxing bout in next month before resuming his Super Rugby career with the Chiefs.
The 29-year-old admits it's a punishing schedule but says athletes pushing the limits and maximising their earning potential is part and parcel of modern sport.
Williams says there was a ready market of fans who wanted to see football stars like NSW rugby league captain Paul Gallen having a crack at boxing.
"That's just the sport that it is. As much as it is a sport, it's entertainment as well, said Williams ahead of his heavyweight fight with American Chauncy Welliver in Sydney on January 31.
"Kids these days, these are the players that some of them look up to and they want to watch them get in the ring and these guys want to push themselves.
"They want to make a bit of extra coin on the side to what what they're doing in footy and so be it.
"But everyone's got to realise that it is a dangerous sport as well and that you're one punch from a knockout.
"As I just about found out last fight (against veteran South African heavyweight Frans Botha)."
Arguably the world's most successful dual international, Williams has won a Rugby World Cup, a Super Rugby title and NRL premierships with two different clubs.
In his well-qualified opinion, Williams gave Sam Burgess's defection from the NRL to English club rugby the thumbs up.
But he was unsure if the Englishman would make the transition in time to make an impact at next year's Rugby World Cup.
"Obviously being the special athlete that he is, he's going to make it," Williams said.
"But it's just about how long the time-frame does he have. It's just how long will it take.
"So it's not a matter of if, it's a matter of how long from my perspective.
"You have his coach from Bath saying that he wants to play (Burgess) in the forwards and obviously his English coach wants him to play No. 12 (inside centre), so who knows.
"But I know he'll make it, but it's a matter of how long."
Williams has spent most of his rugby league career in the back row, playing only sparingly in the centres.
In rugby, though, he has played almost exclusively in the backs, mostly in the centres but also successfully on the wing during the 2011 World Cup.
"I played 30 minutes (in the back row) when I was in Toulon and I had to put the head gear on," he said.
"I'm not too sure if Sammy likes to put the head gear on.
"But it's cool to see players stepping out of their comfort zone and having a go, especially players at the top of their game.
"You've got Jarryd Hayne over (attempting to break) in the NFL. These type of things open doors and avenues for players that they never (previously) thought about.
"Although the rugby league fraternity probably don't like it, the rugby union fraternity probably doesn't like it, it's cool for sportsmen, for young kids coming up to know that there's not just that one door."