Wallabies coach Dave Rennie is sweating on the fitness of James O'Connor and Matt To'omua as preparations ramp up for the opening Test match on July 7.
This comes after scrumhalf Nic White was ruled out of the three-Test series against France with a MCL injury to his knee.
O'Connor is still battling a neck injury that kept him out of the final two games of Trans-Tasman, leaving him stranded on 99 Super Rugby games.
He has remained in camp as he receives treatment as he prepares to return to training in the coming days
Meanwhile, To'omua has left camp for Canberra after aggravating a neck complaint he picked up during Trans-Tasman.
With both players set to be assessed over the weekend, Rennie was confident the youthful squad could step up if they were absent.
“It’s a possibility. Obviously, neither of them have done a lot of training with us,” Rennie told reporters when asked about the duo playing in the first Test.
“We have some big days, got through a lot of training. We’ve got some good young men in here as well who will be applying pressure for selection.
“You’ve got to plan to be without them and we will know a bit more by the end of the weekend how Matt returns and James recovers.”
If ruled out, it would likely leave Brumbies flyhalf Noah Lolesio as the main option to take the number ten jersey.
However, there continues to be discussion circulating around who should fill in at scrumhalf in White's absence.
Jake Gordon is making rapid progress from his own MCL injury and could be available for his home Test, however, he will be eased back into action.
This likely leaves a battle between Tate McDermott and Ryan Lonergan, with the Wallabies coach talking up both options.
“He’s a good player and played in some big moments for the Brumbies,” Rennie said on Lonergan.
“He’s a smart kid and it’s been good having him in this environment. We brought him in as cover for Jake and obviously, we’re hanging onto him and he’s going really well.
“…Tate’s got an outstanding running game and that’s the standout. He’s been working on those core skills around his passing and kicking skills.
“He’s had a big season, his communication and ability to bark and challenge the guys around him has really developed. We’ve got a couple of good options.”
WHITEOUT:White out of French series.
TOUCHDOWN:France arrive in Sydney
Rennie and the Wallabies staff are pushing the 38-man squad across the near month-long camp, with players undergoing up to five seasons per day across a 12 hour period.
As they look to turn around the Wallabies fortunes, Rennie was confident they are adequately managing players workloads ahead of the impending Test calendar.
“From a sports science and strength and conditioning point of view, we have some of the best people in the world so we’re monitoring everything,” he added.
“We’re certainly challenging them and keeping an eye on guys individually. There are some who are in fantastic shape whilst others we’re pushing to make shifts.
“We’re comfortable that we’re ticking all the right boxes."