‘They’re desperate’: Why the All Blacks can take ‘risks’ in Bledisloe II

Insisting there's plenty on the line in Saturday's Bledisloe Cup dead rubber, Sam Cane says the All Blacks believe they'll face a "desperate" Wallabies side in Dunedin.

The All Blacks can continue their perfect preparation for the World Cup against Australia, with three wins on the trot this season.

Those victories have bagged New Zealand the Rugby Championship for a third straight year and kept the Bledisloe in Kiwi hands for an incredible 21 straight editions.

It also means Ian Foster has a Test to play with selection, and he's done so, making 12 changes.

While some have interpreted it as disrespectful to Australia, All Blacks legend John Kirwan said it was a natural benefit of putting the Bledisloe to bed.

"Success has to give you some carrots and this is one of them," he told AAP.

"The beauty of winning all those trophies is now you can take a few more risks."

Kirwan said he believed the All Blacks would be far from a second XV.

"It's not a B-Team. The locking partnership has over 200 Tests. Ardie (Savea) is out there as will Damian McKenzie, who I believe will be our first five moving forward," he said.

"Shaun Stephenson has been outstanding form in Super Rugby. He's getting his chance. Anton Lienert-Brown is really, really solid, and so is (Braydon) Ennor."

Kirwan called Foster's selection as "courageous" and All Blacks captain Cane agreed, calling it "bold", scoffing at the suggestion there was little to play for.

"For one, we've got three guys ... making their debut. And a lot of guys have an opportunity," Cane said.

"We know that where we're at right now is not what's going to be good enough later in the year.

"So every time that we get a chance to take the field as a team, it's a chance to take a step forward and get better and then ultimately get to where you want to get to."

Cane, who missed the 38-7 MCG win through injury, said the All Blacks were most pleased by their defensive effort in Melbourne, holding the Wallabies to just one try.

He said he expected an improved Australian showing on Saturday afternoon.

"They're desperate, and we know that," he said.

"At this level, every team, generally, the more time you spend together, you're able to make small improvements each week in training and so they'll be better again."

Kirwan said Saturday was a "free hit" for both sides.

"I thought the Wallabies were really, really good for 20 minutes in the first half. I thought they were naive in the second half," he said.

"Sometimes you want to play a style of rugby that you're not quite ready for.

"But Eddie has got to stick with some of the young guys he's got there and just build a rugby team."