Neill to captain Australia against Costa Rica
Neill, 35, had come under considerable scrutiny following his poor performances in the successive 6-0 defeats against Brazil and France.
He was also heavily criticised in some quarters for questioning the desire and ambition of his younger international team-mates ahead of the Socceroos' most recent outing, a 3-0 friendly win over Canada in London.
Both Robbie Slater and Mark Bosnich called publically for the centre-back to stand down, but Neill has shown no inclination to call time on his career, and it appears Postecoglou is willing to give the former Blackburn Rovers and West Ham United player the opportunity to prove his worth.
"He's the captain tomorrow, we've still got a session to get through tonight but Lucas will be starting and he'll skipper the side tomorrow night," Postecoglou said on Tuesday.
The coach added when asked how long he deliberated over the captaincy decision: "Not too long. I know it's been a fascination in terms of the decision but to be honest, and I've said it all along, there are more important priorities for us right now, particularly for me as the new coach coming in.
"Everything we've done has really been about the collective, it's about the whole group making sure we're on the same page and going down this journey together.
"My whole focus is trying to get this whole group up and running, so the individual things within that such as the captaincy is a fascination (for the public) at the moment which I sort of understand but it hasn't really taken up a lot of my time or thought.
"With Lucas starting tomorrow night it was pretty logical, in fact there wasn't a decision to be made as far as I was concerned."
But Postecoglou confirmed Neill's appointment is only for the Costa Rica clash, having yet to decide on his long-term skipper.
"I've said all along they're all one-offs, who's guaranteed about being around next time in any position?" he said.
"As I said, I think there'll be a lot more time spent by other people thinking about who the captain is than me."
Neill, who will break Peter Wilson's record of 60 caps as Socceroos captain against Costa Rica on Tuesday, also attempted to deflect attention from his own appointment.
"I wasn't worried (I would lose the captaincy), I've been honoured to do it 60 times," Neill said.
"As the manager's just said, this is not about any individual, in fact it's not even about the team now, it's about the country.
"We're in an exciting time, six months out before a World Cup and it's about Australia, it's about everybody.
"I have a training session to get through tonight and I'll be honoured to lead the team out tomorrow night if that is the case.
"But there are more important things. We have to start Ange Postecoglou's era in a very positive way.
"We've tried to buy in to all the things he's been talking about in training, his style that he's trying to implement on us, and it's up to us now to embrace that and go out and perform the best we can in the manner that he expects."
It remains to be seen where Neill will be playing next year.
Linked with a move to Adelaide United, he is reportedly in negotiations to extend his stay at J-League club Omiya Ardija.