Aaron Cruden is likely to slot into fly-half after Dan Carter was ruled out (Getty) © Getty Images

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He sets rugby records for breakfast but raising a century of Tests is turning into an arduous challenge for fragile All Blacks playmaker Dan Carter.

A calf strain will sideline Carter from both Bledisloe Cup Tests against Australia this month and leaves him in some doubt for two subsequent Rugby Championship home Tests against Argentina and South Africa.

Coach Steve Hansen did not want any chances taken after a post-training scan on Monday revealed damage that will sideline Carter for up to month. It should see Aaron Cruden promoted to No.10 for the opening Test against Australia in Sydney on Saturday.

Cruden started two of the three home Tests against France in June because Carter was battling a hamstring niggle. The 31-year-old suffered his latest knock at the same training ground where he famously collapsed in agony with a groin injury during the 2011 IRB World Cup, ruling him out of the rest of that tournament.

He has since battled a host of niggles, reducing his Test output and prompting an announcement last week that he will take a six-month break from rugby after the All Blacks' tour of Japan and Europe in November. That tour is now the earliest that the he can bring up 100 Tests, a tantalising scenario which reminds him of a cricket batsman starved of strike before reaching three figures.

"I've had a few injuries in the 90s so I guess I'm nicking a few through to the slips," he said. A pragmatic Carter says his recent experience of overcoming niggles leaves him confident of being fit for the Test against Argentina in Hamilton on September 7.

"It's a bit frustrating, especially when the body feels good. Running on it over the next few days is only going to make it worse. It's important I do the rehab so it's not ongoing for the rest of the year."

Carter is Test rugby's leading point-scorer with 1399. His 322 points against the Wallabies is comfortably the most by any player against another nation. Hansen emphasised the length of the break is precautionary. The strain is at the lighter end of the scale but a recurrence of it could be potentially serious.

"It sounds dramatic because he's been there before, I guess, and because it's three-four weeks," he said. "It just reiterates why he needs to have this extended break. So he can go away and get all the niggles dead right."

Inside-centre Ma'a Nonu trained well again on Tuesday, suggesting he has overcome an ankle injury. However, Hansen is now concerned about cover at No.12, with Carter slated as the man to shift out one spot if Nonu can't play. One possibility is to promote uncapped Crusaders back Ryan Crotty from a wider training group role into the Test 23. Crotty was called into the squad on Sunday in place of the injured Francis Saili.

I don't seem to have much luck with injuries when I'm in Wellington #rehabtime

— Dan Carter (@DanCarter) August 13, 2013