SYDNEY, Dec 29 (Reuters) - Novak Djokovic has pulled out of the Serbia team for the ATP Cup in Sydney, event organisers 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.
Organisers of the Australian Open, which starts on Jan. 17, have stipulated that all participants must be vaccinated against the coronavirus or have a medical exemption granted by an independent panel of experts.
"Novak Djokovic has officially withdrawn from the ATP Cup in Sydney, we have no update as yet on his plans for the Australian Open," a Tennis Australia spokeswoman said in an emailed statement.
"Regarding the medical exemption process, which pertains to all players, there is a rigorous and independent process in place. As with all medical information it is subject to confidentiality."
The global men's tennis governing body ATP did not immediately respond to a request for comment.
ATP Cup organisers said Serbia's team would now be led by world number 33 Dusan Lajovic.
Owing to Djokovic's current world ranking, Serbia received top billing for the 16-team event, which runs from Jan. 1-9, and have been drawn in Group A along with Norway, Chile and Spain.
Djokovic has won a record nine Australian Open titles, including the last three, and is in a three-way tie on 20 major titles with Roger Federer and Rafa Nadal in the all-time list.
His father Srdjan told a Serbian television channel last month that Djokovic would probably pull out nL4N2SK0VQ of the major, saying Tennis Australia's stance on mandatory vaccination was tantamount to "blackmail".