Paceman Peter Siddle has been ruled out of the second Test against South Africa, starting in Hobart on Saturday, with a back injury.
Joe Mennie appears set to make his Test debut in Siddle's absence, while Tasmania quick Jackson Bird has been placed on standby for the squad.
"Peter Siddle had some lower back soreness at the conclusion of the first Test Match in Perth," said Bupa Support Team Physiotherapist David Beakley.
"Whilst we expect bowlers to be sore after Test matches, this was slightly worse than we expected and given that he was returning from a significant back injury, we organised some scans today.
"The scans demonstrated some low grade bone oedema around his old stress fracture that is likely to be a flare up of his previous lower back injury.
First Test wash-up: Every player rated
"We are hopeful that this will resolve relatively quickly, but have withdrawn him from the squad for the second Test Match in Hobart.
"We will monitor his recovery and have a better idea of when he will return to play in the next week or so."
It will mean there will be at least two changes to the Australia XI for the second Commonwealth Bank Test in Hobart, after opening batsman Shaun Marsh was ruled out with a finger injury. Queenland's Joe Burns and South Australia's Callum Ferguson had already been called into the side for the trip to Tasmania.
Quick Single: Aussies call for reinforcements
Siddle was out of action for eight months following back and ankle problems and the series opener against the Proteas was just the second first-class match in his comeback following Victoria's round one Sheffield Shield clash with Tasmania, in which he bowled 26 overs.
The 31-year-old got through 38 overs in Perth as South Africa pummelled the Australians in their second innings to forge a match-winning lead, meaning the hosts' quicks had been forced to bowl on each of the first four days of the contest.
"We're very tired," Siddle admitted after play on day four. "Bowling every day of a Test match is hard work.
"As a fast bowler you always want to have a day or a bit more just to rest up and recuperate and get back onto it.
"They kept us out in the field, they took their time … they wore us down … we'll turn up tomorrow, we'll see how we're feeling, but a rest would be nice."
Siddle was a somewhat surprise inclusion in the XI for the first Commonwealth Bank Test, with the Victorian admitting in October he was unsure as to whether he'd be available for the opening Test following his lengthy layoff.
"It just comes down to how much cricket I can play before that first Test, more so than how I'm feeling," Siddle said last month. "It's about playing long-form cricket and getting two, three, four spells in a day and then having to back up the next day and go again in the second innings.
"Whether they (selectors) take me along to that first Test or I just keep working and get ready to play a part hopefully somewhere throughout the summer, we'll know more in the next couple of weeks."
Quick Single: Alarming trend in Australia's Test slump
Former Australia paceman Ryan Harris objected to the idea that Siddle – and perhaps Mitchell Starc – who bowled 49.4 overs in the searing Perth heat after also returning from injury – weren't adequately prepared for the first Test.
"It's easy to say that now – if they'd taken five-for each it wouldn't have mattered," Harris said. "They're probably better off being underdone than overdone, put it that way; I used to always go into a game preferring to have not bowled as much because you want to be fresh.
"Should they have bowled a few more overs? Maybe.
"But they wouldn't have played them if they didn't think they were ready."
Australia squad for Second Test: David Warner, Joe Burns, Usman Khawaja, Steve Smith (c), Adam Voges, Mitchell Marsh, Callum Ferguson, Peter Nevill, Mitchell Starc, Josh Hazlewood, Joe Mennie, Nathan Lyon, Jackson Bird (standby)
International cricket is more affordable than ever this summer, with adult tickets from $30, kids from $10 and family packages from $65 across every day of international cricket. Price for purchase at match. Transaction fee from $6.95 applies to online and other purchases. For more information and to purchase tickets, click here.