All Black flyhalf Dan Carter says he is looing forward to playing alongside a supersized centre pairing on Saturday.

An injury to incumbent All Black outside centre Conrad Smith has seen coach Steve Hansen pair up Sonny Bill Williams and Ma'a Nonu in midfield for the weekend’s Rugby Championship/Bledisloe Cup opener in Sydney.

Carter, who has experience playing with both behemoths, says he takes comfort in having two big ball-carriers outside him.

"It's not bad looking outside and seeing the likes of Sonny Bill and Ma'a, a couple of absolutely huge human beings," Carter said.

"Hopefully we'll get some front foot ball and be able to use them going forward."

Carter missed the last meeting between the two sides in last year’s World Cup semifinal and says he is eager to tackle their trans-Tasman rivals again.

"It was pretty frustrating what happened last year and obviously I'm pretty keen to make the most of this opportunity," Carter said.

"To be over here in Sydney and playing against a strong Wallabies side is a great challenge."

Nonu, standing in for Smith, knows he has big shoes to fill. "Obviously I've got big shoes to fill with Conrad having held that jersey for a long time and hopefully I can do him proud," he said.

The injured Smith has been helping Nonu with the finer aspects of outside centre play, putting a particular importance of the subtle yet crucial differences on defence.

"I was always on his case, he's so wise in decision-making really and he's pretty much the best 13 [centre] defensively in the world I think.

"You can't get caught out [on defence]," he said. "We've got a few systems in place but you have just got to try and control the outsides.

"Everyone will be talking about the Australian backline being new and fresh and not attacking, but if we put ourselves in their shoes they'll be playing at home with their backs against the wall and that is where someone is dangerous, so we have to watch out."