2021 Australian Open finalists Novak Djokovic and Daniil Medvedev have both refused to commit to next year's tournament amid uncertainty surrounding the status of unvaccinated players.
Both men have not publicly revealed their COVID-19 vaccine status, but Victoria premier Daniel Andrews recently warned that unvaccinated players would not be given the green light to play.
The 2022 edition of the Australian Open is set to begin in January, but neither Djokovic nor Medvedev have confirmed their participation in the Grand Slam.
Speaking to the press, Medvedev said: "I always said it, that I really like Novak's answer about this. I want to keep my medical, no matter if it's about vaccine, leg injury, head injury... I want to keep my medical private for a reason.
"I feel like tennis is such a brutal sport where you're always one on one against your opponent, and any information you give him can go against you.
"If you're playing Australia, it's obvious you're vaccinated. So that's why I said I'm willing to play Australia, but I won't say if you'll see me there, but we're going to see in January."
Djokovic adopted a similar stance, telling reporters: "Right now we don't have any official announcement or statement. So until that's out, I won't be talking about this anymore."
The Serbian defeated Medvedev 7-5 6-2 6-2 in the 2021 final to win his ninth Australian Open title, and his third on the bounce.