The Socceroos begin their Asian Cup campaign on home soil with the tournament opener against Kuwait on Friday, with speculation mounting over the hosts' formation and starting XI.
Attacking midfielder James Troisi hinted this week the boss could opt to field two playmakers in the curtain raiser at AAMI Park, but his coach was quick to clarify that the primary objective is to achieve variation in the final third.
"I'm pretty sure we've only got one number 10 shirt and there'll only be one number 10 out there," he said.
"I think players get a little bit carried away with numbers and positions. What we have tried to do is have a little bit more fluency in the front third, have less players playing in set positions.
"We tell James it's a 10 because that's where he wants to play but it's not really that, so don't tell him," he joked.
Postecoglou went for a 4-2-3-1 at Brazil 2014, with Mathew Leckie and Tommy Oar playing as wide forwards either side of Tim Cahill.
And while right-sided attacker Robbie Kruse has since returned to full fitness, traditional wingers could face a battle to be picked in the new-look national team.
"We've been evolving it since the World Cup," Postecoglou said.
"We want to play with a real fluency up front and some rotations in the way our strikers play. Sometimes that'll mean them taking up non-traditional striking positions.
"We still need width but we might get width from different players and different positions. Part of it is we don't want the opposition to get set against us if we've got plenty of movement."
Postecoglou also issued a stern warning to any players with one eye on their next move at club level.
"I'd be very surprised if any of the boys are thinking about anything else but what's before them in the next month," he said.
"Obviously it's the January window, I wouldn't think too many of our boys are worried about where they're going to be at the end of this month.
"If anyone's distracted by anything else then it just means somebody else will take their position. And I don't think anyone in our squad at the moment wants anything more than to play that first game and be part of this team. I don't see distractions coming into play."
