If you correctly predicted Australia's starting line-up against Turkey, the next thing you should've done was buy a lottery ticket.

Tony Popovic dropped Socceroos captain Mathew Ryan to the bench. Again. He did it in his very first match in charge, a crucial World Cup qualifier against China in October 2024. That set the tone for a tenure marked by radical selections, calculated gambles, and an apparent indifference to public opinion.

During his 20 months as coach, Popovic has called up players many thought were finished and overlooked others viewed as automatic picks. Almost every squad announcement has produced at least one decision that left fans scratching their heads.

In the alternate universe where Australia lost to Turkey in their Group D opener, he would've been savaged for leaving Ryan and Jackson Irvine — Australia's two most experienced leaders — out of his XI. But in this universe, Popovic looks like a genius, and the scrutiny that would've followed a defeat has been replaced by something far more valuable: trust.

“People spoke probably bad about him before Turkey. I don't know if they did — I'm saying maybe,” Socceroos defender Alessandro Circati said. “He sort of just shut them all up, because we got a result. So at the end of the day, he plays, depending on the game, for the result and for the win, and that's it, really.”

That is key: the idea of a “first XI” doesn't seem to exist for Popovic. He's looking for a best XI — not in the sense of who are the best players, but who are best suited for the specific job required against a particular opponent.

The United States play a different way to Turkey, and have different strengths and weaknesses. A different approach will be required on Saturday (5am AEST) against the World Cup co-hosts at Seattle's Lumen Field. That could mean different personnel or different tactics, or most likely both.

For a guy obsessed with the finest details, it's hard to imagine Popovic doesn't have something else up his sleeve for the Americans.

“I don't think you're going to show all your cards in the first game of the group stage,” said utility Kai Trewin. “Obviously there were a lot of things that we did well, and we're trying to just keep building on that and keep improving as the tournament goes on.”

Trewin describes the 2-0 win over Turkey as the best football memory of his career, even though he was an unused substitute. That sense of selflessness is what makes Popovic's chopping and changing sustainable.

It wouldn't work if Ryan and Irvine had viewed their omissions as a slight and became negative influences. Instead, they accepted Popovic's decisions and helped drive the team from the sidelines.

“There were some big calls from the boss but those boys did well, and the boys that weren't playing were completely 100 per cent positive towards the boys that [were] playing,” Trewin said. “That wouldn't happen if we weren't all on the same page.”

There's plenty of talent yet to see the field for the Socceroos: Ryan, of course, plus Barcelona target Lucas Herrington, attacking maverick Ajdin Hrustic, veterans Mathew Leckie and Awer Mabil, and Cristian Volpato, a late arrival into World Cup camp who's still improving his fitness base.

“You see Cristian's quality every day since he's come in. He's a really top, top player,” Trewin said. “If he gets his opportunity, I'm sure he's going to do a good job.”

So what does Popovic have planned for the US? Nobody knows. But if his track record is anything to go by, it'll be something unexpected — and it just might work.