World number one Novak Djokovic has committed to playing the ATP Cup in Sydney amid ongoing uncertainty over his title defence at next month's Australian Open.
Djokovic has been unwilling to confirm his place at January's Australia Open due to the COVID-19 mandate in Victoria.
The state of Victoria, where the year's opening grand slam takes place at Melbourne Park, has introduced a vaccine mandate for professional athletes and across most industries due to the coronavirus pandemic.
Djokovic's father, Srdjan, said the nine-time Australian Open champion is unlikely to feature in Melbourne unless vaccination rules are relaxed.
But in a boost for the slam's organisers, Djokovic was named in top-seeded Serbia's team for the third edition of the ATP Cup, which will take place in Sydney from January 1-9.
"We're excited to host the third edition of the ATP Cup in Sydney in 2022," said ATP Cup tournament director Tom Larner.
"The playing group enjoy representing their countries and to see 18 of the world’s Top 20 players commit to the event is testament to that.
"The event shows off the passion the playing group have for this format and we look forward to welcoming all 16 teams to Sydney later this month."
The 2021 Australian Open went ahead, albeit in February instead of January, and without fans for most of the tournament following a snap lockdown of Melbourne due to COVID-19.
Djokovic – winner of a joint-record 20 grand slam titles – was among the players critical of the conditions athletes endured prior to this year's Australian Open, with strict quarantine measures introduced.