After months of speculation that Novak Djokovic may miss the Australian Open over tough Covid vaccination requirements, the world number one was on Tuesday named to play in a Sydney tournament weeks before.
The 20-time Grand Slam champion had cast doubt on whether he would defend his title at Melbourne Park next month, refusing to reveal whether he was inoculated against coronavirus.
However, he was listed as part of the five-man Serbia team when the draw was made for the ATP Cup in Sydney that will precede the opening major of the year.
Rafael Nadal was missing, with the Spanish fellow 20-time Grand Slam winner last month suggesting he would play an exhibition in Abu Dhabi this month, then another tournament before arriving in Melbourne for the Australian Open.
The only other absent top 20 player for the 16-team ATP Cup was injured Swiss great Roger Federer.
"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," said tournament director Tom Larner. "The event shows off the passion the playing group have for this format."
An ATP statement accompanying the draw noted that top seed Serbia was "headlined by world number Novak Djokovic", who won three of the season's four Grand Slams.
The 34-year-old ended his rollercoaster season with a Davis Cup defeat last week and then promised to make a decision on his Australian Open participation "very soon".
Organisers of the Australian Open have insisted only fully-vaccinated players will be allowed into the country, which saw Djokovic's father Srdjan last month suggest his son "probably won't" play.
"Of course he would want to go with all his heart," he told Serbian television.
"But I really don't know if that will happen. Probably not under these conditions, with this blackmail and when it's done that way."
Djokovic contracted Covid-19 during the ill-fated Adria Tour event he organised in the Balkans in June 2020, but said he did not suffer from any symptoms.
Russia are the defending ATP Cup champions after their team spearheaded by Daniil Medvedev and Andrey Rublev swept past a Matteo Berrettini-led Italy in the final.
Djokovic's Serbia won the inaugural event in 2020, overpowering the Nadal-led Spain.
The teams in next year's US$10 million event, from January 1-9, are divided into four groups of four, playing across two Sydney venues -- the Ken Rosewall Arena and Qudos Bank Arena -- with each tie comprising two singles matches and one doubles.
Top seeds Serbia were grouped with Spain, Norway and Chile, while Russia will face Italy, Austria and home nation Australia.
Germany, led by reigning ATP Finals champion Alexander Zverev, headline Group C against Canada, Great Britain and the United States, while Greece, featuring world number four Stefanos Tsitsipas, are in Group D with Poland, Argentina and Georgia.