Novak Djokovic has won the Australian Open nine times in his career, but new vaccination requirements could prevent him from competing in the tournament in January.
"Under these blackmails and conditions, he probably won't [play]," Novak's father, Srdjan Djokovic, told Serb TV (via BBC Sport). "I wouldn't do that. And he's my son, so you decide for yourself."
Australian Open tournament director Craig Tiley announced last week that players not vaccinated against COVID-19 would not be allowed to participate in the 2022 event.
Djokovic has not revealed whether he is vaccinated.
"Doesn't really matter whether it's vaccination or anything else in life," Djokovic said earlier this month. "You should have the freedom to choose, to decide what you want to do. In this particular case, what you want to put in your body."
The 34-year-old still has the freedom to choose not to get a vaccination, but if so, he wouldn't be permitted to compete in the first Grand Slam of the season, which starts Jan. 17.
Djokovic would be the clear favorite if he does compete as the No. 1 player in the world ranking and the three-time defending champion of the event. The superstar is also looking to break a tie with Rafael Nadal and Roger Federer for the most major singles championships in men's tennis history.
All three currently have 20 career Grand Slam titles.
Tiley previously projected 85 percent of professional players have been vaccinated and he expects 90-95 percent to get a shot by January, per BBC Sport.