Wellington - The much-hyped Hurricanes flank Ardie Savea has been thrust into the All Blacks limelight with confirmation on Sunday that injured Sam Cane will be out of action for at least a month.

Even in a country renowned for producing world-class number sevens, notably the recently retired Richie McCaw, Savea has been regarded as someone exceptional ever since he made his provincial debut four years ago as an 18-year-old.

He was singled out by New Zealand coach Steve Hansen as a special project the following year when he selected Savea as an "apprentice" to sample the All Blacks atmosphere on their 2013 northern hemisphere tour.

The younger brother of blockbusting wing Julian Savea eventually sampled Test rugby with bit parts off the bench in five internationals this year.

Now he has been elevated to be lead contender as openside flanker for the Rugby Championship clash with South Africa next weekend, with Cane sidelined for four to six weeks by the hamstring injury he suffered in Saturday's 57-22 victory over Argentina in Hamilton.

While Savea is rapidly gaining cult status in New Zealand with his immense pace and power, Hansen, however, is keen to downplay expectations.

"It's a big step up from Super Rugby to the more physical demands of international rugby," Hansen said after also calling Crusaders flank Matt Todd into his squad.

"Everyone is happy with the progress but we know there's things he can still do better.

"It's the pace of the game. He's a really explosive athlete so is he ready to play 80 minutes? We're not sure yet at that level but we'll get a good 60 out of him and we know Matty can play for as long as we need him."

The All Blacks could claim the Rugby Championship crown with two games to spare if they register a bonus-point win over South Africa, with Hansen tipping Australia to finish second on the ladder.

The Wallabies snapped a six-game losing streak with a 23-17 win over the Springboks on Saturday and Hansen expected them to beat Argentina next weekend.

"It's about who is going to bounce back the best and you'd suggest Australia are in a better position because they come off a win and they'll be feeling good about themselves after struggling," he said.

Argentina "will maybe go into their shells a wee bit but it'll be a good contest because if they both turn up they've got contrasting styles".