All Black superstar Sonny Bill Williams feels he is getting good at juggling two sporting careers - rugby and boxing.

Williams and fellow World Cup winner Richard Kahui assembled with the rest of their new Super Rugby squad, the Chiefs, in Hamilton this week.

For the next four weeks Williams will have to juggle being a rugby player by day and a boxer by night, as he prepares for a heavyweight boxing bout in early February.

Speaking to Newstalk ZB Williams said he can maintain a balance between his two sporting endeavours.

"I sat down with Dave [Rennie, head coach] and the rest of coaching staff before the season started, so we just nutted out [discussed] a plan and it's coming into place right now," he said, adding: "A tough sparring session at night but it's all about learning the systems and plays and everything and working hard."

Williams says his four week boxing camp in Sydney has been successful.

The utility back said he is also aware of the hype around the Chiefs this year.

"Obviously we'd like to win the title, but there's other things that have got to fall into place before that happens.

"There will be a lot of hard work as well, so we've just been nutting out the game plan - the things we need to put in place to even think about getting into the top six or winning the Final."