The 28-year-old has been officially ruled out of the tournament due to a knee injury sustained in Huddersfield Town's English Premier League defeat to Arsenal earlier this month.

An independent assessment involving Socceroos physiotherapist determined Mooy would not be fit until after the quarter-finals and coach Graham Arnold reluctantly opted to go with a player who would be ready from the outset of the tournament.

Austria-based midfielder James Jeggo, who debuted for the Socceroos in last month's friendly against Lebanon in Sydney, will replace Mooy.

The news is a blow for Arnold, with young gun Daniel Arzani already out of the tournament due to a knee injury suffered while playing for Scottish Premier League club Celtic.

The Socceroos coach expects Jeggo to fulfil a defensive midfield role.

"James has thrived at club level playing in a defensive midfield role and with three attacking central midfielders already in the squad, we felt we needed someone with James' attributes to provide some depth in that area," Arnold said.

Tom Rogic appears to have overcome a knee problem with his Scottish Premier League Celtic even appealing to FFA to allow him to play in the Old Firm derby next weekend before he links up with the Socceroos, a request unlikely to be granted.

There's encouraging news too for Mathew Leckie after he limped off with a hamstring injury during Hertha Berlin's Bundesliga clash with Bayer Leverkusen on the weekend.

Leckie will join the Socceroos camp in the UAE in the coming days and undergo an assessment by Australia's medical team.

An initial assessment has indicated Leckie's injury won't prevent him playing for the Socceroos in the tournament.

Australia's Asian Cup campaign starts against Jordan in Al Ain on January 6.

Australian Associated Press