Australia leads Pool C but isn't yet guaranteed a quarterfinal place and captain David Pocock said the Wallabies can't afford to look any further ahead than Georgia.
Bernard Foley and Christian Leali'ifano have previously started in the No. 10 jersey in Australia's wins over Fiji and Uruguay and its loss to Wales. Cheika will now try To'omua, who has started only four of 50 test matches at flyhalf.
Leali'ifano combined with White against Fiji and Uruguay while Foley paired with Will Genia against Wales.
Cheika says his selection changes serve the dual purpose of managing player workload — Leali'ifano played all 80 minutes against Uruguay — and promoting competition for positions.
To'omua is "a different player to Leali'ifano and Foley," Cheika said. "He's got a different style and (he's) a different type of defender and he's done well in the opportunities he's been given."
Foley and Leali'ifano haven't yet been able to preside over the 80 minute performance Chieka has been looking for and he now hopes the 29-year-old To'omua, in his first start at flyhalf since November, might be able to guide a more complete performance.
"This is how we think this squad is best is to keep giving opportunities to guys to keep the contest alive with others," Chieka said. "So if we do the right thing and get through knockout stages, we know everyone's been a part of doing their bit.
"Some want to go with the same players all the time and maybe rest out. We feel like keeping players competing for spots is working for us. I think we're playing some good footy."
Cheika doubts that selection instability has contributed to the Wallabies' slow starts.
"It's not like we're not playing well there," he said. "We're creating opportunities at starts of games but we're not capitalizing on them.
"That just takes that little bit of extra concentration on staying in the moment. I think sometimes in the game we're thinking about the bigger picture of the game.
"Obviously, other teams are coming hard at us because they know it's an opportunity to try and get us there, so we've just got to lift our standard there, it's pretty simple."
Georgia and Australia's meeting on Friday will be their first in tests.
"They're very physical, that's quite obvious," Cheika said. "It'll be a really good challenge for us.
"A lot of players play in professional leagues in France, England as well. They"re well attuned to competition at a high level.
"It"s really exciting to be part of the first time two countries have ever faced off. We want to show them how we play our rugby and I'm sure they'll be showing us how they play theirs."
Michael Hooper was a late withdrawal from the Wallabies bench due to "general soreness".
- AP
Match details: Pool D, Friday, October 11, 11:15pm Shizuoka Stadium Ecopa, Shizuoka Prefecture.
Referee: Pascal Gauzere (France)
Squads
Australia:
15. Kurtley Beale, 14. Jordan Petaia, 13. James O'Connor, 12. Samu Kerevi, 11. Marika Koroibete, 10. Matt To'omua, 9. Nic White, 8. Isi Naisarani, 7. David Pocock (c), 6. Jack Dempsey, 5. Rory Arnold, 4. Izack Rodda, 3. Sekope Kepu, 2. Tolu Latu, 1. Scott Sio
Reserves:
16. Jordan Uelese, 17. James Slipper, 18. Taniela Tupou, 19. Rob Simmons, 20. Lukhan Salakaia-Loto, 21. Will Genia, 22. Christian Lealiifano, 23. Dane Haylett-Petty.
Georgia:
15. Soso Matiashvili, 14. Giorgi Kveseladze, 13. David Kacharava, 12. Merab Sharikadze (c), 11. Alexander Todua, 10. Lasha Khmaladze, 9. Gela Aprasidze, 8. Beka Gorgadze, 7. Mamuka Gorgodze, 6. Beka Saginadze, 5. Konstantine Mikautadze, 4. Giorgi Nemsadze, 3. Beka Gigashvili, 2. Shalva Mamukashvili, 1. Mikheil Nariashvili
Reserves:
16. Jaba Bregvadze, 17. Guram Gogichashvili, 18. Giorgi Melikidze, 19. Otari Giorgadze, 20. Giorgi Tkhilaishvili, 21. Vasil Lobzhanidze, 22. Lasha Malaguradze, 23. Tamaz Mchedlidze
Who was the best in Black? Rate the All Blacks' performance against Namibia.
The Herald will have live updates of the match from 11.00pm. Spark Sport coverage starts at 10.45pm. Kickoff is at 11:15pm.
Head-to-head
Australia and Georgia have never played before.
Prediction: Australia by 29.
Group standings