Bledisloe Cup rugby: Wallabies first-five James O'Connor ruled out as Dave Rennie makes seven changes for All Blacks clash in Sydney

The Wallabies have been dealt a huge blow with No 10 James O'Connor out injured for their do-or-die Bledisloe Cup clash against the All Blacks in Sydney on Saturday.

O'Connor, who hardly trained during the week for the Aussies, was ruled out with a knee injury, meaning 20-year-old playmaker Noah Lolesio makes his debut at first-five.

The injury blow comes after Matt To'omua suffered a groin injury in the second test in Auckland, which has seen centre Irae Simone also make his debut for Dave Rennie's side.

Rennie has made five changes to his starting side and a further two to his bench, with Reds duo Fraser McReight and Tate McDermott also set to make their test debuts.

"It's really exciting to be able to name four more debutants in the squad this week," Rennie said.

"Noah and Irae have played a lot of footy together and we have no doubt they're ready to take the step up to Test rugby."

"Tate and Fraser have had big Super Rugby seasons and have impressed in training over the past month," Rennie added.

Wallabies coach Dave Rennie with Nic White. Photo / Photosport

The Wallabies will wear their First Nations jersey on Saturday, just the second time since debuting the kit in their famous win in Brisbane in 2017.

"It's an especially significant night for us with the chance to represent and celebrate our First Nations people by wearing the Indigenous jersey on home soil in front of our Wallabies family," Rennie said.

"We know New Zealand will pose another tough challenge but we've prepared well and will be ready to go on Saturday night."

Wallabies team: James Slipper, Brandon Paenga-Amosa, Allan Alaalatoa, Lukhan Salakaia-Loto, Matt Philip, Ned Hanigan, Michael Hooper (c), Harry Wilson, Nic White, Noah Lolesio, Marika Koroibete, Irae Simone, Jordan Petaia, Filipo Daugunu, Dane Haylett-Petty

Reserves: Jordan Uelese, Scott Sio, Taniela Tupou, Rob Simmons, Fraser McReight, Tate McDermott, Reece Hodge, Hunter Paisami