Socceroos defender Alessandro Circati has ruptured his ACL in an early blow to new coach Tony Popovic's bid to turn Australia's World Cup qualification campaign around.
Italian club Parma confirmed Circati, 20, injured his left knee at training on Friday.
He is expected to have surgery, which would rule him out of Australia's entire third round of qualifying, which finishes next June.
"The Parma Calcio medical staff can confirm that Alessandro Circati suffered an injury during the team's training session at the Mutti Training Centre in Collecchio this morning," Parma said in a statement on their website.
"Tests revealed that the defender has ruptured the anterior cruciate ligament in his left knee.
"Everyone at Parma Calcio hopes to see Alessandro back helping his teammates on the pitch as soon as possible. Forza Ale, speedy recovery!"
Circati posted on his Instagram story, writing: "Recovery starts now, thanks for all the messages and support."
Highly rated central defender Circati was crucial to Parma's promotion from Serie B to Serie A and had settled into Italy's top-flight with aplomb.
He was used at right-back by former coach Graham Arnold in qualifiers against Bahrain and Indonesia, but is expected to be a long-term centre-back for Australia.
The injury robs Circati of potentially a year's development and playing time, meaning Popovic - a former top central defender in his own right - won't be able to call on him early in his tenure.
In the short term that will include the October 10 match against China in Adelaide and a blockbuster clash with group C leaders Japan in Saitama five days later.
Popovic, who was only appointed last week, will now have to consider his right-back options with Harry Souttar, Cam Burgess and Kye Rowles his leading central defenders.
If Australia qualify directly for the 2026 World Cup - an uphill task after claiming just a point from their opening two games - Circati would likely return via friendlies.
Otherwise, he will be racing the clock to feature in the fourth round of qualifying, which is scheduled for next year October.
The Perth-born youngster will, however, be able to lean on Souttar, who returned from tearing his ACL in qualifiers in time to play at the 2022 World Cup in Qatar.
Souttar went on to take his career to new heights at the global showpiece, playing a crucial role in Australia's run to the round of 16.
