Novak Djokovic will be deported after the world No.1 lost his appeal to stay in the country.
A lucky loser is set to replace Djokovic, the No.1 seed, who was scheduled to take on fellow Serb Miomir Kecmanovic on Rod Laver Arena on Monday night after women's world No.1 Ash Barty's clash with Lesia Tsurenko.
But with Djokovic now out of the tournament, it's understood a lucky loser - a player who lost during qualifying and was then put on standby in case of injury - will now be a direct replacement.
Djokovic faces deportation from Australia after his last-minute challenge to a decision to cancel his visa failed. The three-judge panel of the Federal Court ruled unanimously against Djokovic on Sunday evening.
It came after Immigration Minister Alex Hawke had cancelled Djokovic's visa for a second time on Friday afternoon, citing a risk to public health and the chance the unvaccinated star's presence in Australia could excite anti-vaccination sentiment.
The Australian Open order of play is normally released two days before the start of the tournament. But the uncertainty over Djokovic's prospects of playing saw them delay the schedule until just after 4 pm AEDT on Sunday.
The Federal Court still hadn't made their ruling by that stage, leaving AO organisers with little choice but to schedule the match for prime time on Rod Laver Arena. It's unclear how Djokovic's dramatic exit will now affect the scheduling.
The delay in the order of play release meant players have been kept in the dark as to whether to prepare for a day or a night match. World No.8 Casper Ruud wasn't too fazed by the delay.
"Usually on the ATP tour (apart from grand slams) you don't really know until the evening before," Ruud said.
"I've been trying to practice a little bit in the morning, and a little bit in the afternoon and the evening to get a feeling of both scenarios.
"I've been trying to mix up the days a little bit, some later sessions and some earlier."
Women's defending champion Naomi Osaka will play unseeded Colombian Camila Osorio in the second match of the day session at Rod Laver Arena, before former men's champion Rafael Nadal plays American Marcos Giron.