Sonny Bill Williams undergoes chest surgery

Sonny Bill Williams's fight with Francois Botha has been postponed after the New Zealander had surgery to correct a chest complaint.

Williams, who also plays rugby in Japan, was due to take on Botha next month.

Despite having to cancel the bout, Williams is confident that he will be able to rearrange the meeting for some time in February.

"Just spoke to the doctors operation went well, Thanks for the support I've been truly blessed," he wrote on Twitter.

Botha has previously taken on Lennox Lewis, Mike Tyson and Evander Holyfield.