Djokovic Skips ATP Cup, Adding to Australian Open Uncertainty

Novak Djokovic of Serbia returns against Jenson Brooksby of the United States during the fourth round of the U.S. Open tennis championships in New York on Sept. 6, 2021. John Minchillo/AP Photo

SYDNEY—Novak Djokovic has pulled out of the Serbia team for the ATP Cup in Sydney, event organizers said on Wednesday, raising further doubts over whether the world number one will defend his Australian Open title next month.

There has been intense speculation over Djokovic’s participation in both events, with the 34-year-old, who is opposed to COVID-19 vaccinations, repeatedly declining to say if he has been inoculated against the virus.