But a plan for the 35-year-old O'Connor, back in the green and gold after three years, to share the No.10 role has had to be shelved after Ben Donaldson went down injured in training on Thursday.
The idea had been for O'Connor to play the first 40 minutes with Donaldson coming on after the break but the injury has left the Wallabies looking at risky alternatives in the playmaking department as they get set to face the world champions in Johannesburg on Saturday (Sunday AEST).
"In the second to last play of the training, 'Donno' kicked the ball and pulled up short so we don't know what the extent of the injury is," coach Joe Schmidt revealed after naming the team.
"We've only been back from training for about an hour so he will get a scan now and we'll have a definitive picture because we need to know for next week as well whether we need more cover.
"Nic White can cover No.10 and is astute enough to do so, Andrew Kellaway has the skill set as well if we go with what we've got at the moment."
The inclusion of the 35-year-old O'Connor at No.10 is the only change to the starting XV that defeated the British & Irish Lions 22-12 in Sydney a fortnight ago, as he comes into the side after Tom Lynagh suffered a concussion in that encouraging victory.
O'Connor, who helped New Zealand outfit Crusaders win the Super Rugby title this season, hasn't played for the Wallabies since 2022 but still looks the safest pair of hands after all the fly-half woes Schmidt has had to contend with, what with first-choice Noah Lolesio also out with neck trouble.
O'Connor's halfback partner will be another veteran, White, who has doubled back on his decision to retire after the Lions series when first choice Jake Gordon got injured.
Donaldson's injury has necessitated a late change to the planned bench with Schmidt having to replace the versatile back with loose forward Nick Champion de Crespigny.
That means Australia will go from a five-three to six-two split between forwards and backs among the replacements.
Yet Schmidt sounded upbeat as he noted: "The group has had a good week of preparation, adjusting pretty well to the time zone and the altitude well here in Johannesburg.
"There's not many bigger Tests than playing South Africa on their home turf and we know we're going to need to be at our best on Saturday night."
Australia are seeking their first win at Ellis Park since 1963, when they beat South Africa 11-9.
Australia team:
15–Tom Wright, 14–Max Jorgensen, 13–Joseph Suaalii, 12–Len Ikitau, 11–Dylan Pietsch, 10–James O'Connor, 9–Nic White, 8–Harry Wilson (captain), 7–Fraser McReight, 6–Tom Hooper, 5–Will Skelton, 4–Nick Frost, 3–Taniela Tupou, 2–Billy Pollard, 1–James Slipper
Replacements: 16–Brandon Paenga-Amosa, 17–Angus Bell, 18–Zane Nonggorr, 19–Jeremy Williams, 20–Langi Gleeson, 21–Nick Champion de Crespigny, 22–Tate McDermott, 23–Andrew Kellaway.
