The Australians will co-host the 32-team finals in July and August next year with neighbours New Zealand, and Gustavsson warned against complacency ahead of his side's latest preparation matches.
The Matildas lost the first of two matches against Olympic champions Canadians 1-0 on Saturday in front of a crowd of 25,016 at Lang Park in Brisbane. The teams meet again in Sydney on Tuesday.
"Everyone talks about 'it's almost a year to the World Cup'," Gustavsson told reporters.
"But we actually broke all the FIFA windows down and we have five FIFA windows, that means we have 46 days.
"Out of those 46 days, 14 days go to travel and recovery. That leaves us with 32 days. Out of those 32 days before the World Cup roster is announced, it's going to be 11 games and 11 pre-game sessions.
"That leaves us with 10 proper training sessions; 10 sessions where we can play 11 v 11 and work on all the details.
"That's how soon we're going to announce a roster (before) coming here and preparing for the World Cup.
"So it's around the corner. Every minute counts."
Gustavsson takes his team into the games against the Canadians with a host of key players missing as Ellie Carpenter, Hayley Raso, Steph Catley, Tameka Yallop, Chloe Logarzo, Caitlin Foord, and Kyah Simon are all sidelined.
The Australians have won only eight of the 24 games they have played since Gustavsson was appointed in 2020, but the Swedish coach called for more backing for his team from the country's sporting community.
"When you believe, it means you can achieve something that is more than expected of a team," he said.
"And the one thing (that) is for certain is I have this job because I believe in this team, and I know the process we're into, the players believe in the process, and believe in this team as well.
"Look at what England did in the Euros, for example, with the home nation supporting them. If we can believe, then it's going to be a very, very interesting World Cup."
