New Zealand's rugby player Sonny Bill Williams smiles as he talks to the media during a press conference in Auckland, New Zealand, Wednesday, Oct. 19, 2011. New Zealand play France in the Rugby World Cup final on Sunday, Oct. 23. (AP Photo/Dita Alangkara)

Auckland – Sonny Bill Williams may be quitting New Zealand after the All Blacks play the Wallabies here on Saturday but the star midfielder is reluctant to say it's forever.

“Who knows what the future holds?” he said as he looked back on a stellar three seasons since returning to New Zealand to chase his “dream” of playing for the All Blacks.

He achieved that with last year's World Cup-winning All Blacks and added to his trophy cabinet with a Super 15 crown this year playing for the Waikato Chiefs.

If the All Blacks defeat the Wallabies in their Rugby Championship match on Saturday he will add the Bledisloe Cup, the symbol of trans-Tasman rugby supremacy.

Then, the player who rose to fame playing rugby league in Australia before chasing bigger money with rugby union in France heads to Japan on a brief, but lucrative, union contract before returning to rival code league in Australia.

Williams's departure for Japan has already been delayed after All Blacks coach Steve Hansen negotiated his availability as cover for the injured Conrad Smith in the first two Rugby Championship matches against Australia

“The dream wasn't over when Steve rang me and said a couple more weeks, but next week it will definitely hit me... but in saying that, who knows what the future holds?”

All Blacks captain Richie McCaw and coach Steve Hansen both say they would not be surprised if Williams does return to New Zealand rugby.

“It is a shame (he's going) because he is just showing how much of a force he is on the international stage in rugby,” McCaw said.

“From our point of view it was great to have him last week and again (on Saturday) but he's always said you never know what's around the corner for him so he may be back. I'll not be surprised.”

Williams has not always been a crowd favourite with rugby passionate New Zealand supporters because of a perceived preference to put high-dollar contracts ahead of loyalty to the jersey.

But Hansen is a big fan of the multi-talented star and backs Williams – who is also developing a career as a professional boxer – to return to New Zealand rugby.

“The New Zealand public are pretty good at recognising someone who's doing the job and he's done that,” Hansen said after Williams sealed the Chiefs' Super 15 title with a late try in the final against South Africa's Coastal Sharks.

“One or two are a bit anti and think he's chasing the money but he's a professional sportsperson. You only get a very short term in your playing career to make money... he's entitled to do what he's doing.

“It's not his fault that he's pretty good at boxing and people want to watch him do that. It's not his fault he's good at league and it's not his fault that people want to put a contract in front of him.

“I'd be confident enough to say that I don't think it's the last time he will play for the All Blacks, either. I think he will come back. – Sapa-AFP