Sonny Bill Williams will reveal his future plans tomorrow.

There will be a press conference at the Chiefs' headquarters in Hamilton at 11.45am tomorrow, where Williams will announce his next move, which will be to play for Japanese club Panasonic in a deal worth a staggering $1.7 million.

Williams' name has appeared on a list of registered players for next season's Japanese Top League, meaning his deal with Panasonic is completed.

After his time in Japan, Williams will play for the NRL's Sydney Roosters in a deal that is expected to be around $640,000. He also has the potential to rake in another $640,000 from two more boxing fights over the next 12 months.

As the Japanese season starts in a few months, Williams won't sign with any provincial union and it is unlikely he will be considered for the All Blacks again this year. Despite playing so well in the three-test series against Ireland last month, All Blacks coach Steve Hansen needs to look to the future and not just towards this year's Rugby Championships.

But Williams, who was off limits to the media after the Chiefs' 28-21 loss to the Crusaders on Friday night, will want to finish off his time in New Zealand on a good note by helping the franchise win their first ever Super Rugby title.

Williams and his manager, Khoder Nasser, have only ever been interested in signing one-year deals in the past, but Nasser's other big-name client, Quade Cooper, recently put pen to paper on a three-year deal with the Australian Rugby Union and Queensland Reds, and it will be interesting to see how long Williams commits to the Roosters for.

If he returns to the NRL for two years, it does give him the option of returning to New Zealand the following year, and having another crack at the All Blacks in time for the 2015 World Cup in England.