World number one Novak Djokovic will not travel to Sydney for the men's season-opening ATP Cup next week, Serbian daily Blic reported on Saturday.
Djokovic was named in Serbia's team for the ATP Cup, although the 34-year-old has yet to commit to the Australian Open following the organisers' mandate for COVID-19 vaccinations.
Djokovic has declined to disclose whether he is vaccinated, citing privacy.
Serbia are in Group A along with Norway, Chile and Spain at the ATP Cup, which is scheduled for Jan. 1-9 before the Australian Open begins on Jan. 17.
Australian Open chief Craig Tiley said on Wednesday that he is still uncertain whether Djokovic will be playing at the Melbourne Park major.
Tiley has said that all players and staff at the Australian Open would be vaccinated or have a medical exemption granted by an independent panel of experts.
Those requirements have prevented Djokovic from confirming whether he will bid for a men's record 21st Grand Slam title and a 10th Australian Open crown.
