Harry Kewell has been ruled out of Tuesday's World Cup qualifier against Thailand, in which Australia need to pick up a point to book their place in the next round.
Kewell was injured during Friday's shock 1-0 loss to Oman in Muscat and was replaced in the 54th minute by Robbie Kruse.
The Melbourne Victory star was found to have aggravated a muscle strain and coach Holger Osieck and medical staff agreed to let the 33-year-old return home for treatment. The extent of the injury is unclear at this stage.
Australia have two matches remaining to gain the point they need to secure their place in the next round of qualifying.