The biggest crowds of Day Three are expected to gather for the four Australians in action at Melbourne Park, where wildcard Emerson Jones will face former Wimbledon champion Elena Rybakina.
Top men's match: Fritz vs Brooksby
Fourth seed Fritz comes into the tournament fresh off winning the United Cup in Sydney with the United States and looking to build on a strong 2024 season where he reached the US Open and ATP Finals title deciders.
Fritz remains the favourite to break a US trophy drought in men's Grand Slams which stretches into its 22nd year but the 27-year-old is taking things one game at a time.
"Last year I was happy with all my slam results. I want to treat it the same way," the American number one said.
"The worst thing I can do is be looking super far ahead in the draw."
Brooksby is coming back from an 18-month doping suspension for whereabouts failures, which was reduced to 13 months on appeal.
The 24-year-old has not played since the 2023 Australian Open but he will surely take inspiration from his victory over Fritz at the US Open in 2021.
Top women's match: Rybakina vs Jones
With no Australian woman inside the top 100 and the country seeking an heir to 2022 champion Ash Barty, Jones is their next best bet as the junior world number one makes her Grand Slam debut at 16 as a wildcard.
"I think it's great when people say that I'm following in Ash Barty's footsteps... Obviously, it's going to take a lot to get where she was," said Jones, who claimed her first Tour-level match win in Adelaide last week.
Jones faces former Wimbledon champion Rybakina, who arrives in Melbourne facing questions about the provisional suspension of her former coach Stefano Vukov.
She is also looking to "stay healthy" after skipping many tournaments last year.
"I was not able to participate in big events. For me to play from the beginning till the end of the year... I want to win big titles, this is my goal on court," she said.
No place like home for De Minaur
De Minaur kicks off the night session at Rod Laver Arena against Dutchman Botic van de Zandschulp and the Australian number one said there was nothing better than starting the season on home soil.
"As Australian tennis players, we spend the majority of the year overseas. To get the chance and opportunity to start the year here at home in the summer, it just means the world," he said.