Barrett suffered a concussion in the All Blacks' thrilling 25-24 win against South Africa in Cape Town on October 8 and was forced from the field late in the first half.

Team officials said the No.10 passed concussion tests at the time but in the week afterwards Barrett started to feel the effects of the knock.

The All Blacks will monitor Barrett throughout the week and make a call regarding his availability, likely to be on Thursday, when they name their team to take on the Wallabies.

Lima Sopoaga, who has only started one Test from 12 appearances, is in line to take Barrett's position if the 26-year-old does not pass all the necessary tests.

Crusaders five-eighth Richie Mo'unga has been called into the All Blacks camp as cover for Barrett and could make his Test debut for the third and final Bledisloe Cup match in Brisbane on Saturday.

All Blacks coach Steve Hansen may instead opt to push Damian McKenzie into the No.10 role if Sopoaga were to be subbed off, rather than putting Mo'unga on the bench.

Meanwhile, All Blacks second-rower Brodie Retallick has ruled himself out of the Test, again opting to stay in New Zealand.

Retallick did not play his side's last match in South Africa so he could be with his family after he and his partner lost their unborn son.

Scott Barrett is in line to fill Retallick's spot in the second row.

Another second-rower Luke Romano has remained home in New Zealand after he and wife Hannah welcomed a baby boy into the world.

As a result, Patrick Tuipulotu will stay with the squad as a replacement for Romano, while Matt Todd will remain in the squad that boasts three No.7s.

The All Blacks will be looking to knock off the Wallabies for the third time this year after a 54-34 victory in Sydney and a hard-fought, come-from-behind 35-29 win in Dunedin.

New Zealand have beaten Australia in their past seven outings in a winning streak that stretches back to August 2015 before a famous World Cup final win at Twickenham.

Kieran Read's men have dominated world rugby since the last World Cup, losing just two of their past matches, with one of those defeats coming against the British and Irish Lions in July.

All Blacks squad for Australian tour: Wyatt Crockett, Kane Hames, Nepo Laulala, Jeff Toomaga-Allen, Ofa Tu'ungafasi, Dane Coles, Nathan Harris, Codie Taylor, Scott Barrett, Patrick Tuipulotu, Samuel Whitelock, Sam Cane, Vaea Fifita, Jerome Kaino, Kieran Read, Ardie Savea, Liam Squire, Matt Todd; Tawera Kerr-Barlow, TJ Perenara, Aaron Smith, Beauden Barrett, Richie Mo'unga, Lima Sopoaga, Ryan Crotty, Ngani Laumape, Anton Lienert-Brown, Sonny Bill Williams, Rieko Ioane, Waisake Naholo, David Havili, Damian McKenzie.