Whether it pays off remains to be seen but, according to Jackson Irvine and Milos Degenek, Postecoglou's confidence is contagious.
A day after Australia's 4-0 loss to Brazil, Postecoglou raised eyebrows by stating his intent to win the tournament ahead of the three fancies - World champions Germany and continental champions Portugal and Chile - and his players are buying in.
"Going into a tournament with eight teams, if you're not here to try and win it, what's the point?" Irvine said from Sochi.
"Anything is possible. We believe in our ability.
"That's one of the major things we've changed within this group ... to always be positive and have that winning mentality."
Degenek said he admired his manager's ambition.
"The boss has the right to say that and I believe in that as well," he said.
"You don't want to go to a tournament to say that you've been there and to swap a few jerseys with big players.
"The point is to come here to make an impact and make a statement ... so people start talking.
"So other people in the world start talking about us as a team and a country.
"We're here to win it. We're not here to have fun, experience Russia and its beauty."
Australia's lofty goals will be tested in their opener with Germany on Tuesday morning (AEST).
The World No.3 side has brought a younger squad, resting several seasoned internationals ahead of next year's World Cup.
Degenek, who spent five seasons in Germany and counts several members of Die Mannschaft as friends, says that doesn't make them any easier to beat.
"I don't think they've brought an understrength team," he said.
"All their players played a full season in the Bundesliga (or) one of the top leagues in the world.
"They're missing some of their bigger players but that doesn't change much. They've got the same mentality, the German mentality which is a very good one."
Australia hit the track on Friday for their first run-out in Russia.
Late call-ups Jimmy Jeggo and Alex Gersbach - brought into the squad as injury replacements for Mile Jedinak and Brad Smith - linked up with the group and trained fully.
Robbie Kruse, who had his knee strapped, spent time alone with a physio while the rest of the squad trained together.