Injury could spell premature end to Sonny Bill Williams' Japanese deal - and Botha boxing bout

Rugby World Cup winner Sonny Bill Williams' return to club action in Japan could be in doubt - after undergoing surgery which also looks set to postpone his next boxing bout.

The All Blacks centre, who is expected to return to rugby league next year, was due to fight former heavyweight title contender Francois Botha in Brisbane next month.

But the 27-year-old suffered a shoulder and chest injury while playing for club side Panasonic Wild Knights and underwent pectoral surgery today.

"Just spoke to the doctor operation went well," he said on Twitter.

"Thanks for the support I've truly been blessed,"

Williams - New Zealand's heavyweight boxing champion - faces up to two months out, which would put his fight with 44-year-old Botha on the shelf, and potentially spell a premature end to his lucrative club rugby contract.

Williams left the world champion All Blacks and Waikato Chiefs for the Japanese side worth an estimated $100,000 (Dh367,000) a game, but is just halfway through the 12-match deal.