Christian Lealiifano's chances of playing in the first Test against England are diminishing as Wallabies coach Michael Cheika whittles down his backline options.
Nine players will be trimmed from Australia's 39-man squad after Friday's training session - the last at their Sunshine Coast base before operations move to Brisbane.
If Lealiifano - still in Canberra with his pregnant wife Luga, who is overdue by more than a week to give birth to their first child - isn't able link with the team by Sunday, chances are he will too will be excluded for the first Test at Suncorp Stadium on Saturday week.
Cheika is staunchly family-first and there is no pressure being placed on the Brumbies skipper, one of the leading candidates for the vacant inside centre role.
But assistant coach Stephen Larkham said they would soon have to finalise team combinations.
"It's the birth of his first child and it's very important for him to be there," Larkham told AAP.
"Realistically if he's not here, and there's no pressure on him to come, it's his decision - but if he's not here next week, we start moving on to a different combination.
"We're giving him every chance to have the baby and come back."
After a few days of experimentation, Larkham said the Wallabies were down to two possible centre combinations.
"We just need to see how they progress over the next two days," he said.
It all depends on whether Cheika wants a second playmaker - like Lealiifano - at No.12, or to delegate that role to the fullback and field a big ball-runner to batter the English from inside centre, such as Israel Folau, Samu Kerevi or Tevita Kuridrani.
"The style we play, we certainly like to have two ball-players out there," Larkham said.
"But in saying that, knowing what England are going to bring with their physicality, we have that ability to change the game up by picking guys who can run the ball rather than pass the ball.
"That's the decision we need to make over the weekend."
Larkham injected himself into Thursday's session as the team tried to test out their new structures in spite of the absentees, including Lealiifano, Mike Harris (hamstring) and Karmichael Hunt (groin).
Hunt is yet to train with the main group since the Wallabies came together and hasn't played for nearly a whole month, having picked up a groin strain during Queensland's Super Rugby loss to the Crusaders on May 6.
Cheika is understood to be giving Hunt every chance to prove his fitness ahead of what would be his Test debut and it's not expected he will be among those culled on Friday.