Experienced fullback Andrew Kellaway will make his first appearance of the Rugby World Cup with a new halves pairing also suiting up for the Wallabies in their must-win match against Wales in Lyon.
Coach Eddie Jones has relegated Carter Gordon to the bench after he struggled in their historic loss to Fiji last round, shifting Ben Donaldson from fullback to 10 for the clash on Sunday (Monday AEST).
Tate McDermott returns after a head knock to partner Donaldson, although, oddly, the vice-captain will not take over the captaincy in the absence of Will Skelton with hooker Dave Porecki retaining that honour.
Jones said Kellaway would be key against a Welsh team expected to kick a lot in the OL Stadium match.
The selection of Kellaway, who was the Wallabies' first-choice at 15 before the World Cup when Jones opted for Donaldson due to his goal-kicking, is the only change to the starting backline.
"He's a smart player, reads the game well and against Wales, particularly, who are exceptionally high kicking team," Jones said of 24-Test Kellaway.
"I think his composure and his ability to read the game well is going to be important."
Jones said the change at five-eighth was designed to "freshen up" the Wallabies' stuttering attack.
"We just feel we needed to probably freshen the team up," the coach said.
"Carter's had an opportunity, struggled a bit against Fiji and I thought that he's best to finish the game for us."
Sitting third in the pool with one win and one loss to start their campaign, the Wallabies need victory over unbeaten Wales or will crash out before the quarter-finals for the first time.
Jones said he had absolute confidence they would beat the men in red, who downed Australia in their pool clash at the 2019 tournament in Japan.
"We were always going to get this game at some stage and it's come a little bit earlier than we thought it would, so we've got an opportunity to show on Sunday whether we can fight and really grind out and get the result we need to get," Jones said.
"I've got no doubt we'll win, got no doubt the way the team's prepared, the way they've come together, I've got no doubt we'll win on Sunday."
Retaining the same tight five from Fiji, Rob Leota starts his first Test of the year at blindside flanker.
Tom Hooper has shifted to openside and Rob Valetini at No.8 with Jones looking for a heavier back row with the Wallabies out-muscled at the breakdown by Fiji.
Fraser McReight, who has started both World Cup matches in the No.7 jersey, will come off the bench.
Wales veteran coach Warren Gatland was equally optimistic about his team's chances of toppling the embattled Australians.
He restored the line-up which started the win against Fiji after resting most in their scratchy victory over Portugal.
"I expect us to win on Sunday," Gatland said.
"We've trained well this week. We've been clear on what we want to achieve. We haven't been at our best so far."
Australia: Andrew Kellaway, Mark Nawaqanitawase, Jordan Petaia, Samu Kerevi, Marika Koroibete, Ben Donaldson, Tate McDermott; Rob Valetini, Tom Hooper, Rob Leota, Richard Arnold, Nick Frost, James Slipper, David Porecki (c), Angus Bell. Reserves: Matt Faessler, Blake Schoupp, Pone Fa'amausili, Matt Philip, Fraser McReight, Nic White, Carter Gordon, Suliasi Vunivalu.
Wales: Liam Williams, Louis Rees-Zammit, George North, Nick Tompkins, Josh Adams, Dan Biggar, Gareth Davies; Taulupe Faletau, Jac Morgan (c), Aaron Wainwright, Adam Beard, Will Rowlands, Tomas Francis, Ryan Elias, Gareth Thomas. Reserves: Elliot Dee, Corey Domachowski, Henry Thomas, Dafydd Jenkins, Taine Basham, Tomos Williams, Gareth Anscombe, Rio Dyer.
