A member of the green and gold backroom staff believes his team are facing one of the best sides at the tournament when they clash with Oranje this week
Socceroos supporters had hoped to come up against Dutch team still finding their feet in Brazil after a recent cycle of regeneration, with an inexperienced defence earmarked as a potential weakness.
But any chance Australia had of catching their opponents unprepared were dashed when they watched 'Oranje' annihilate reigning world champions Spain 5-1.
That result would perhaps have been slightly less of a surprise to Vidmar than others, with the Socceroos assistant having tipped this group of Netherlands players to already be playing close to their potential.
"Van Gaal has changed a lot of players over the last couple of years and through the qualifying period as well. He's brought in a lot of young players as well. They've probably already got past that first stage of their regeneration," he told Goal Australia.
"They're going to be a very tough proposition. You can never take any team for granted. We've got an enormous amount of respect for them because they were the last World Cup's finalists.
"They've got a lot of experience around them. There are a few that haven't played a lot of internationals, but they've got a lot of tough experience from domestic competition, which will also put them in good stead.
"They'll be very, very motivated as well to do very well. Regardless of whether you play with one cap or thirty or forty, when you go to a World Cup, it's a fresh start. Everyone's going to be extremely motivated."
Vidmar also dismissed any suggestion Van Gaal's impending departure to Manchester United after the World Cup will affect his players during the tournament.
"I don't think that's going to make much of an impact," he said.
"Coaches come and go. He's not the first one to say that he won't be coaching a national team and going to club land after a World Cup.
"They'll be, like every other team, trying to do their very best and win games. We're not different. You can't get involved or take that emotion into your thinking and into your game. That's their business, that's what's going to happen. And the players, their players, will go out there to before at the very best."