Former sevens star Darby Lancaster will make his Test debut on the wing with former All Blacks prop Alex Hodgman in line to make his first appearance for Australia off the bench on Saturday.
Prop Allan Alaalatoa will be Schmidt's third captain in as many weeks, after fellow forwards Liam Wright and James Slipper had the armband for the two Tests against Wales.
Schmidt said back-rower Wright's shoulder injury was taking a bit longer to heal than he would like and prop Slipper copped a shoulder knock last week, but could have played if it was a final.
Back-rowers Fraser McReight and Rob Valetini and backs Hunter Paisami, Filipo Daugunu and Tom Wright are the only starters retained from last week's second Test run on side against the Welsh.
"I think today we lacked a little bit of cohesion because when you do make those many changes and lose a bit of your rhythm and that's a risk for us," Schmidt said.
"But if we don't do it then we're not quite sure where we sit with some of the guys in the squad."
Coach Joe Schmidt gives some instructions during a Wallabies training run. (Dean Lewins/AAP PHOTOS)
Most of the changes were voluntary, though Schmidt said a few players had copped bumps and bruises last week and others like halfback Jake Gordon had totted up plenty of "mileage" across the year.
Schmidt emphasised the need to look at different players, while appreciating the importance of Australia maintaining their winning start to the season.
"It's an impossible balance to get near right because you're not sure till the team goes out there if you've done the right thing," he said.
"You have to have faith in the changes and we've got faith in the changes, we do believe that we are putting a good side out."
Alaalatoa will be joined in the front row by Issac Kailea and Billy Pollard, both of who will start for the first time along with lock Angus Blyth.
Lock Nick Frost, No.8 Harry Wilson and centre Len Ikitau will play their first Tests of 2024, with Frost partnering Blyth whilst Wilson joins McReight and Valetini in the back row.
Schmidt said Lancaster was fast and enthusiastic and felt Saturday's Test would move along the speedster's career.
"The only way you can try to kickstart a career is to put them in the cauldron," Schmidt said.
Ben Donaldson sees open space during the Wallabies' 2023 World Cup pool match against Georgia. (Andrew Cornaga/AAP PHOTOS)
In the backs, Ben Donaldson gets his first shot as starting five-eighth under Schmidt with Noah Lolesio dropping to the bench and Tate McDermott taking over from Jake Gordon.
Hodgman is set to become the fourth player to play for both New Zealand and Australia.
"He had a little bit of an up and down season with the Reds with injury, but when he was available I thought he did a good job," Schmidt said of Hodgman.
WALLABIES:
1. Isaac Kailea, 2. Billy Pollard, 3. Allan Alaalatoa (capt), 4. Nick Frost, 5. Angus Blyth, 6. Rob Valetini, 7. Fraser McReight, 8. Harry Wilson, 9. Tate McDermott, 10. Ben Donaldson, 11. Darby Lancaster, 12. Hunter Paisami, 13. Len Ikitau, 14. Filipo Daugunu, 15. Tom Wright. Reserves: 16. Josh Nasser, 17. Alex Hodgman, 18. Zane Nonggorr, 19. Tom Hooper, 20. Jeremy Williams, 21. Nic White, 22. Noah Lolesio, 23. Andrew Kellaway.
