Van Marwijk will trim his training squad from 27 to a final 23 for the 2018 FIFA World Cup on Sunday - 48 hours after tonight’s (AEST) penultimate test run against the Czech Republic in St Polten, Austria.
And Luongo - who had van Marwijk waxing lyrical after a commanding performance in the goalless draw against Colombia in March - can rest assured his boarding pass for Russia has been stamped.
The clash against the Czechs will give van Marwijk the chance to make a final call on a number of players and juggle some last-minute options before sacrificing four of his Russia hopefuls.
Luongo, though, appears to be a player he is happy to pin his faith in, while under Postecoglou he was in and out of his starting line ups.
“The obvious difference between the new boss and Ange is that he’s not as intense,” said Luongo of the contrasting characters of the two coaches.
“With Ange you never felt like your spot (in the team) was safe. I feel with a bit more relaxed in that respect with van Marwijk.
“The vibe I’m getting has been good. I think in the first camp in March) maybe I understood quickly what he wanted, and I was able to adapt perhaps faster than some of the other boys.
“Maybe that gave me a bit of an advantage. But as a group of players it’s just a matter of us all adapting and maintaining the same attitude we’ve always had.”
Coming off the most consistent season of his career at Championship club Queens Park Rangers, Luongo only featured off the bench in the 4-1 drubbing against Norway.
But he showed maturity and menace starting against the highly-credentialed Colombians, orchestrating all that was good for Australia at Craven Cottage in a man of the match performance.
“The Colombia game, while it was only a friendly, I felt like I had a little bit more control of the people around me - at club level I’m used pulling people here and there,” added Luongo.
“I have a little bit of a leadership role at QPR and against Colombia we were able to pull players around a bit and have the game suited to us a bit better.”
While he was taken along for a ride to Brazil four years ago by Postecoglou, Luongo, now 25, didn’t get any game time.
He’s come a long way since.
“Confidence wise and mentally I just feel like I’m ready to take on the challenge now,” he said.
“In 2014 I didn’t know what to expect and was pretty nervous. This time it’s different ... I’m more excited than anxious.
“Van Marwijk knows whats required of us as a team to do well because he took Holland to the final in 2010.
“Individually, we are what we are. It’s really all about following the instructions and trying to get what he wants right.
“We have a good group of lads and we won’t let the old regime fade too far.
“Everybody will still be on top of each other and we’ll hold the highest professional atmosphere possible.”
Loungo, often the victim of Postecoglou’s 3-2-4-1 formation is well versed in how van Marwijk wants to play.
“Tactically everybody can see there’s also a difference there ... the boss wants to play a 4-2-3-1 type of system and everybody all over the world plays that formation,” he said.
With bookies ranking Australia as the longest shots of the 32 competing nations in Russia, 34-cap Luongo acknowledges their place in the pecking order.
“We aren’t a Brazil or a Germany,” he said. “At the World Cup we’ll have to be at our best progress - just under our best won’t be good enough. And that’s against Peru - never mind France and Denmark.
“We’re going to need that something extra. We know France can be slow starters but we can’t rely on them not to be great ... we have to figure ourselves on the day and hopefully things click (in their opening game in Kazan on June 16).