Australia's Victoria state will not do special deals with unvaccinated athletes to allow them to compete at major events, an official said on Tuesday, putting Novak Djokovic's Australian Open title defense and bid for the Grand Slam record in doubt.

World No. 1 Djokovic, level on 20 Grand Slam titles with Roger Federer and Rafa Nadal, declined to reveal his vaccination status again this week and said he was unsure if he would defend his Australian Open crown as authorities work out COVID-19 restrictions for the tournament.

Victoria Premier Daniel Andrews said he opposed special arrangements to let unvaccinated athletes compete in the state, which is scheduled to host the Grand Slam at Melbourne Park in January.