Huddersfield star Mooy's omission to the bench was the big story in the hours before the crucial match.
The midfielder was promptly brought on by the beleaguered coach when left back Brad Smith injured his hip flexor in the 11th-minute. The substitution forced a reshuffle in Postecoglou's formation, with Australia grinding out a 2-1 extra time win to set up a play-off against Honduras for a spot at Russia.
Mooy was reportedly angered by his omission, with one report citing a 'source' close to the camp. But the softly-spoken 27 year-old has posted a rare Tweet to clarify his position:
I would like to take a moment to clarify some of the comments that I made post match yesterday, which seem to have been taken out of context— Aaron Mooy (@AaronMooy) October 11, 2017
I was trying to simply make the point that I was disappointed to have not started the match and this is a natural feeling for all players.— Aaron Mooy (@AaronMooy) October 11, 2017
Mooy received an outpouring of support as Australia and Huddersfield fans flocked to the social media network to support him.
Postecoglou meanwhile, is set to step down from coaching Australia in November as the fallout from a campaign approaching its most important moment begins in earnest.