Nick Kyrgios will be a conspicuous absence as Novak Djokovic and Rafael Nadal headline the field at next month's ATP Cup in Melbourne.
A dozen countries, including Australia, who will be spearheaded by Alex de Minaur, will compete in the men's team tournament from February 1-5.
The inaugural event was played last year in Brisbane, Perth and Sydney and won by Djokovic's Serbia over Nadal's Spain, with the world's top two-ranked players squaring off in the final.
Due to COVID-19, this year's entire tournament will take place at Melbourne Park alongside two WTA 500 and two ATP 250 events the week before the Australian Open.
The draw will take place on January 20, when the 12 teams will be divided into four groups of three for group stage round-robin play with each tie consisting of two singles matches and a doubles encounter.
The four group winners will advance to the semi-finals.
Qualification for the 2021 ATP Cup is based on the ATP ranking of each country's top-ranked singles player, while Australia qualifies by virtue of a host-nation wildcard.
World No.23 de Minaur leads the local line-up that made the semi-finals last year.
He will be joined by John Millman, John Peers and Luke Saville, with Kyrgios not taking part after being a hero of last year's campaign.
The two-time grand slam quarter-finalist downed big-hitting German Jan-Lennard Struff, Brit Cameron Norrie and Greece's world No.6 Stefanos Tsitsipas in successive singles victories en route to the semi-finals.
But it was his inspired display partnering de Minaur in a rousing 18-16 third-set super-tiebreak doubles win over Brits Jamie Murray and Joe Salisbury that raised the new roof at Sydney's Ken Rosewall Arena and clinched Australia a last-four berth.
Kyrgios, though, will instead play one of the ATP 250 events in Melbourne, the world No.46 looking for some priceless match practice ahead of the Open.
Kyrgios parlayed his strong ATP Cup form into a fourth-round run at the 2020 Open, finally falling in a four-set thriller to Nadal.
Davis Cup skipper Lleyton Hewitt will once again captain Australia.