Wellington - All Blacks star flyhalf Dan Carter was ruled out of this weekend's Rugby Championship opener against Australia after suffering a calf injury in training, officials said on Tuesday.
Team medics said Carter would definitely miss Saturday's clash in Sydney and the return fixture in Wellington a week later and could be out for four weeks, making him a doubt for Tests against Argentina and South Africa.
The 31-year-old, the highest points scorer in international rugby, said he was disappointed at the injury, which will see Aaron Cruden replace him at number 10.
"It's a bit frustrating, especially when the body feels good and then you have a wee setback like this,'' Carter said.
"So it's always frustrating but, the thing is, I've had injuries like this before so I know what I have to do to get back playing and play as well as I know I can.''
Carter confirmed last week that he will take a six-month sabbatical from rugby next year in a bid to extend his playing career to the 2015 Rugby World Cup.
A major reason for the break was a string of niggling injuries, which sidelined him during the All Blacks' 2011 World Cup campaign and prevented him playing the first two Tests of this year's home series against France.
Coach Steve Hansen was confident Carter would return to help the All Blacks defend the Championship, dismissing suggestions his star playmaker could bring forward the sabbatical.
"I don't think we need to be too keen on getting rid of him. We'll see how he goes over this period," he said.
"The scans show it's not a biggie, it's something that's a nuisance more than anything else."
He said New Zealand had a world-class replacement in Cruden, who had just won back-to-back Super 15 titles with the Chiefs.
"He's ready to rumble," Hansen said. "He's also played a couple of Tests this year and understands what we're trying to do. He's part of the leadership group so it's business as usual."
Beauden Barrett is expected to be named on the bench as Cruden's back-up for Saturday's match.