Crystal Palace captain Mile Jedinak faces a race to be fit for Australia after sustaining an ankle injury in their opening Asian Cup game.
Jedinak, 30, scored a penalty in the Socceroos' 4-1 win against Kuwait in Melbourne on Friday but twisted his left ankle during the first half.
Television pictures in Australia showed the midfielder wearing a protective boot as the team arrived in Sydney.
Australia's next group match is against Oman on Tuesday.
Socceroos coach Ange Postecoglou played down worries over Jedinak and was optimistic the captain would play a part against Oman.
"The medics will have a look at it but hopefully it's nothing that will keep him out," he said.