Socceroos midfielder and Celtic star Aaron Mooy has been ruled out of Australia's upcoming friendlies against Ecuador with a back injury.
Mooy, 32, has been in stellar form for Ange Postecoglou's Scottish Championship leaders but missed Celtic's win over Hibernian on Sunday with back soreness.
After consultation with Socceroos medical staff, it was decided Mooy should remain in Scotland, skipping the friendlies at Sydney's CommBank Stadium on March 24 and Melbourne's Marvel Stadium on March 28.
The friendlies are Australia's first matches after their successful Qatar World Cup, when the Socceroos won two matches and reached the knockout stage for the second time, with Mooy playing a key role.
"It's unfortunate for Aaron that he misses these games, something I know he was very much looking forward to playing, but his absence provides an opportunity to a further emerging player as we start this new campaign," Socceroos coach Graham Arnold said in a statement.
"After speaking with Aaron, who missed this weekend's game, he would only be able to play limited minutes if he came to Australia, so the decision was made for him to stay in Scotland and continue his recovery."
Mooy joins playmaker Ajdin Hrustic on the sidelines, with his absence opening the door for the likes of Keanu Baccus, Cammy Devlin, Connor Metcalfe or potential debutant Aiden O'Neill to earn more midfield time.
Right-back Ryan Strain has been called into the Socceroos' squad as Mooy's replacement.
Strain, who made his Socceroos debut against New Zealand last September, plays in Scotland for St Mirren alongside Baccus.
"Ryan has been playing well for St Mirren and deserves this call-up," Arnold said.
"These matches against strong opposition in Ecuador present us with the opportunity to commence preparations for the next World Cup cycle, which starts again in November, followed by the AFC Asian Cup in early 2024.
"Building depth in the squad is important as we look to build upon what the team achieved at the World Cup in Qatar, and I'm excited by the blend of experience and youth that we've assembled for these two matches."
