The head coach watched on as his side were beaten 3-1 by Chile in their Group B opener on Friday, although Australia put in an encouraging performance against a strong outfit, who many tip to be the tournament's dark horses.
Netherlands demolished pre-finals favourites Spain 5-1 in their first game to stun the watching world but, despite the attacking prowess at Louis van Gaal's disposal, Postecoglou is not planning to adopt a defensive attitude.
"We've said right from the start that's not why we came to the World Cup," he said in a press conference on Tuesday.
"We obviously know we're going to have to be very strong defensively because the Dutch are very dangerous going forward.
"It's going to be an enormous challenge to stop them but the other side of that is, if we try defend for 90 minutes there's only going to be one result and it won't be in our favour.
"From our perspective, it's just as important we're dangerous when we have the ball.
"We'll make sure we're strong defensively but we've spent just as much time working on what we're going to do when we have the ball."
Friday's game against Chile was played in humid conditions in Cuiaba, and Postecoglou believes the cooler weather in Porto Alegre on Wednesday could aid his side.
"I think the players will appreciate it a bit more - the game the other day was played in pretty extreme conditions and it took our players a little bit of time to recover," he said.
"We may make one or two changes, part of that is just the condition of the players so we may make some changes.
"I guess with a cooler temperature you can expect a bit of a quicker tempo and maybe for the game to be a bit more compact than the other night.
"Who's that going to suit? I think both teams like to play attacking football. As for who it's going to suit, I guess we'll see at the end of the game."
