Aaron Lawton - RugbyHeaven
 
Christchurch - All Black Sonny Bill Williams has a stress fracture in his foot and could miss the start of the Super Rugby season next month.

Williams, who says he will be fit for his professional boxing bout against Australian Scott Lewis next Saturday on the Gold Coast, succumbed to a leg complaint in the final game of last year's All Blacks northern hemisphere tour.

He is struggling to run and fears he will not be right in time for the Crusaders' opening match against the Blues on February 19.

''There's still a bit of a problem there and it hurts mainly when I run,'' Williams said. ''I haven't been able to run since the tour. I aggravated it in the last game but it doesn't affect my boxing at all.

''I can still bounce around but when I run at full stride it puts a bit of stress on it.''

Williams has been in close contact with All Blacks doctor Deb Robinson and hopes to resume full rugby training when he returns to Christchurch. He said he injured his leg early on the tour but played on because he was desperate to make his All Blacks debut.

''That was the start of a stress fracture. It was just a little niggle but I could get through on it no problems.''

But Williams said it flared noticeably in the final Test against Wales, when he was subbed early.

''I really started to feel it 10 minutes in. After the game it was pretty sore. I got a scan straight away and was told I was lucky I came off when I did otherwise I'd have ended up with a full stress fracture.''

Williams also revealed plans to fight his next professional bout at home. He said his contract with the New Zealand Rugby Union allowed for one more professional fight in 2011, potentially during the season.