Tony Popovic is calm, comfortable and expecting instant happiness on debut as Socceroos coach.

Popovic's tenure as Australia's coach starts with a vital World Cup qualifier against China in Adelaide on Thursday night.

And despite just having two days with the bulk of his squad to prepare, Popovic is bullish.

Asked how long he expected before being really happy with embedding his systems in the Socceroos, Popovic replied: "Tomorrow.

"I will be happy tomorrow. I am sure I will be happy tomorrow."

While Popovic has been in Adelaide since last Friday, some Socceroos players didn't arrive in the South Australian capital until Tuesday night.

"There's some things out of our control but I don't want to use that as an excuse," he said.

"We feel we have enough time to show the players how we like to play and I'm sure the players have seen that, they're comfortable with it and they'll show some good signs of that tomorrow night.

"The limited preparation, of course everyone talks about that. But that is international football for the players and the staff.

"So we just look at it as finding solutions to the problems that may occur.

"Do it in a real positive manner. Do it with a lot of belief.

"Then we execute tomorrow night and tomorrow night is a chance at home to win the game, beat China, and get three points. And that's our focus.

"Of course it's still very early days. And I'm sure ... that we will definitely see signs of what we want tomorrow night, I'm sure of that.

"And then moving forward, I'm sure we will get better.

"And that's the goal: start tomorrow well, keep improving as we go along."

Popovic's first match in charge carries heavy ramifications for Australia's bid for direct qualification for the 2026 World Cup in Canada, Mexico and the United States.

The Socceroos' horror 1-0 loss to Bahrain on the Gold Coast, followed by scoreless draw in Indonesia in last month's fixtures, leave them in a perilous position.

Those results prompted Graham Arnold to end his eight-year tenure as coach - he announced his resignation on September 20 and Popovic's appointment was revealed three days later.

"It has been everything that I was told to expect," Popovic said.

Australia sit fifth in their group of six nations with just one point - ahead of only China, who have lost both their matches this phase - and travel to play unbeaten group leaders Japan (six points) in Saitama next Tuesday night.

Saudi Arabia (four points) hold second spot and only the top two nations secure direct passage to the '26 cup - the third-placed nation faces another qualifying phase.

"We have to take everything into consideration," Popovic said.

"And we are doing that but we're pretty calm about the process.

"We have got a very good group of players here. I'm very at ease with the decisions that have to be made."