The Swiss-based 25-year-old looms as one of Australia's most important players for the upcoming World Cup qualifiers against Iran and the United Arab Emirates.
Juric is one of only two out-and-out strikers in Postecoglou's 30-man squad, which will be trimmed back by seven players this week, and the only one playing regular minutes.
He has also heard Postecoglou's recent comments about an "alarming" lack of progress in the careers of individual players loud and clear.
Having turned down a big-money move to China two years ago and also rejecting a transfer to English Championship club Reading in January because he wasn't at his physical peak, Juric has already demonstrated his intent to grow as a player instead of chasing money or taking easy options.
"It's up to the individual, at the end of the day," Juric told AAP.
"I know what I want, to try and get myself in one of the best leagues in the world - one of the top five leagues.
"I'm ambitious, I'm here and I'm in Europe and I'm pushing for something big. You never know where things can take you.
"But a lot of our boys are really ambitious. Sometimes choices come upon us and you have to make a decision and that's just the way the footpath leads you."
Juric has been in terrific form for FC Luzern since coming back from a knee injury he suffered last November, which ruled him out of the qualifier against Thailand and interrupted a career-best purple patch during which he emerged as Australia's new No.1 frontman.
But he scored on Sunday against St Gallen - his third goal in seven matches since returning at the start of February - and will likely play one more match in the Swiss league before linking up with teammates in Tehran, where the Socceroos tackle Iraq on March 23.
Juric said he was ready to lead the line for Australia and was pleased to have Postecoglou's confidence despite his recent fitness troubles.
"When your boss is happy with you, he'll encourage you and tell you that you're going a good job," he said.
"This is kind of the same thing, just that the boss doesn't say it - he shows it with his actions and picking you in the squad. The boss has always shown his faith in me."