Postecoglou’s original preliminary 30-man squad included Aziz Behich, Adam Federici, Ajdin Hrustic, James Jeggo, Matthew Jurman and Riley McGree, but along with Jedinak didn't make it into the final 23. 

Jedinak was touch-and-go but failed to recover from a groin injury which also saw him miss the Confederations Cup.

Postecoglou said the Aston Villa man made the call by ruling himself out of the games after contacting him last night.

“We certainly have enough depth in that area of the park to make sure that we can cover his absence,” Postecoglou said this morning.

“He wasn’t involved in the last camp and we’ve made sure that we’ve got a squad of players who are able to fill in when needed.

“It would have been great to have him there, he’s the captain and he’s been a big part of what we’ve done over the last four years.

“He’s been struggling with this little injury for quite a while but kept playing through that with us so you’ve got to give credit to that.”

Postecoglou selected just three A-League players - Tim Cahill, James Troisi and Mark Milligan - with European seasons well under way.

The Socceroos boss said there were never any doubts that European-based stars Tom Rogic, Aaron Mooy and Mathew Leckie would excel at the highest level after recently receiving plaudits for their performances.

Mooy scored his first Premier League goal for Huddersfield against Newcastle United on Sunday

He also admitted it was a tough call to omit Behich and bring back Brad Smith, who missed out on the Confederations Cup due to a hamstring injury.

And with centre-back Matthew Spiranovic now relegated to China’s second division with Hangzhou Greentown, Postecoglou admitted he felt the standard was “not ideal”.

“We believe Matty could certainly be playing at a higher level, but the most important thing is that he is playing,” he said.

“He’s been out of the squad for quite a while. But he does have that experience and that ability to play at this level, we know that.

“With two important games and him playing regularly, we’ll have a look at where he’s at and how he stacks up to the other guys in the squad.”

Four points from the next two games could almost guarantee Australia qualification to the World Cup.

As it stands Japan top the group on 17 points while Saudi Arabia are second, equal on 16 points with Australia, but ahead on goal difference.

The Saudi's host Japan on September 5, the same night the Socceroos play Thailand at AAMI Park.

Postecoglou said they would most likely only get a maximum of two full training sessions in the lead-up to Japan, but sees the game as another opportunity to prove themselves.

The last competitive game between the two nations finished 1-1 in the previous qualifier at Etihad Stadium last year.

“We treat them all like big games so that when you do get into this situation, nothing really changes,” he said.

“They (Japan) need to get a result for this game, everything is on the line, they’re the games you want to be involved in and they’re the games you’ve been preparing for.”