Australia are facing the prospect of going through the remainder of their World Cup qualifying campaign without their captain with Mile Jedinak no certainty to regain fitness before November.

The midfielder was left out of the 23-man squad to face Syria in a two-leg play-off after failing to overcome a groin injury that has hampered his start to the season with Aston Villa.

The veteran has been plagued by the problem since June when he was forced to withdraw from the 2017 Confederations Cup in Russia. He opted to undergo surgery in the hope he would be ready for the vital qualifiers, but did not return for those matches against Japan and Thailand.

Should the Socceroos get past Syria, they will then face the fourth-placed team from North and Central America in the final play-off, beginning on November 6. However, Socceroos coach Ange Postecoglou says the national team is no closer to knowing if Jedinak will be ready for those potential fixtures as his fait lies with Aston Villa.

Complicating matters for Jedinak is the issue of match conditioning. While overcoming injury will bolster his case for a recall, Postecoglou is concerned about his skipper's lack of game time at Villa. As a result of his injury problems, Jedinak has been limited to just one half of competitive football since June.

"I think that's more of a club issue," Postecoglou said. "He's certainly confident he'll be back soon. His club is working hard and Mile does everything right, but it's a matter of ticking those boxes. I'm sure once he's ready he'll play, but in terms of timelines, his club are probably better off speaking about that."

Jedinak will likely overcome his injury before the November international window, however he will have just five club games before then to regain match fitness to be ready for the potential intercontinental play-offs.

"Particularly with the absence he's had from football in general – not just from the Socceroos – I kind of knew he was probably unlikely for these two games [against Syria]," Postecoglou said.

While fitness ruled out Jedinak from this squad, Postecoglou issued an ominous warning to experienced defender Matt Spiranovic that his club career has cost him a place in the national team. Spiranovic was axed from the 23-man squad to face Syria as a result of continuing to play in the second tier in China. The Socceroos coach challenged Spiranovic to find a new club in the January transfer window to regain his place in the national team.

"Playing where he does is a different tempo to the way we want to play," Postecoglou said. "From our perspective, we are really keen to push on with the football we are playing. I am hoping that he plays at a higher standard in the near future and he'll come back into calculations."

Spiranovic is replaced by uncapped defender Matt Jurman, who has impressed playing regularly with South Korean giants Suwon Bluewings. Left back Alex Gersbach was omitted due to a minor injury and was replaced by Turkey-based defender Aziz Behich. Striker Jamie Maclaren was left out in order to help him settle at his new club, Darmstadt, and stake his claim for a starting place, while Nikita Rukavytsya is a surprise recall to the national team after a four-year absence.

Four A-League players are in the squad and will miss the opening round of the domestic season: Melbourne Victory pair Mark Milligan and James Troisi, as well as Melbourne City's Tim Cahill and Western Sydney Wanderers defender Josh Risdon.

Socceroos' squad to face Syria

Goalkeepers: Mat Ryan, Danny Vukovic, Mitch Langerak.

Defenders: Bailey Wright, Trent Sainsbury, Brad Smith, Josh Risdon, Matt Jurman, Milos Degenek, Aziz Behich.

Midfielders: Mustafa Amini, Craig Goodwin, Jackson Irvine, Massimo Luongo, Mark Milligan, Aaron Mooy, Tom Rogic, James Troisi.

Forwards: Matt Leckie, Robbie Kruse, Tomi Juric, Tim Cahill, Nikita Rukavytsya.