Nick Kyrgios has paid the price for a year of inaction over COVID-19 concerns after he was ruled out of Australia's team for next month's ATP Cup after his world ranking slipped to number 46.
The 25-year-old last played a competitive match at Acapulco in February after deciding to remain at home in Australia when the circuit resumed in Europe and North America after a hiatus.
Each nation has two singles slots that will be taken by their top-ranked players and Australia's challenge at the ATP Cup will be led by Alex de Minaur and John Millman who are ranked 23 and 38, respectively.
The duo will be joined by doubles players John Peers and Luke Saville as Australia look to improve on their semi-final finish at last year's inaugural tournament.
The ATP Cup will be held from February 1-5 in Melbourne ahead of the Australian Open, the year's first Grand Slam, and the event will feature world number one Novak Djokovic and second-ranked Rafael Nadal.
"The players are looking forward to stepping up and representing their countries again, and the field, including defending champions Serbia and finalists Spain, is strong," tournament director Tom Larner said.
"This is a format that shows off the passion of the players and we're expecting some spectacular tennis action."
The draw for the ATP Cup will take place on January 20.
Kyrgios, often branded "polarising" for his long rap sheet of indiscretions, had been a galvanising force in raising funds and awareness for Australian bushfire relief efforts during the ATP Cup last year.
He will now play in Melbourne 2, one of two ATP 250 events being held alongside the ATP Cup. Melbourne Park is also hosting two WTA 500 tournaments alongside the event.