A stellar line-up is set to gather in Australia for the first ever ATP Cup, with all of the current top 10 players and 27 of the top 30 committing to play.
World No. 1 Novak Djokovic will partner Dusan Lajovic for Serbia, U.S. Open champion Rafael Nadal teams up with fellow top 10 star Roberto Bautista Agut for Spain and Roger Federer combines with Henri Laaksonen for Switzerland, while Andy Murray continues his comeback from hip surgery, using his protected ranking to allow Great Britain a place in the competition, with the Scot lining up alongside Kyle Edmund.
Daniil Medvedev, Dominic Thiem, Alexander Zverev, Stefanos Tsitsipas, Kei Nishikori and Karen Khachanov round out the current top 10, with Spain (Nadal and Bautista Agut) and Russia (Medvedev and Khachanov) the only teams to boast two top 10 players at the time of writing.
Australia, the host nation, have received a wildcard into the competition, with Nick Kyrgios and Alex de Minaur lining up for the Aussies.
The initial 18 nations have been selected on the basis of the ATP Tour rankings on Friday 13 September, with the top 18 players (or 17, with Murray using his protected ranking of world no. 2) qualifying their countries and joined by the second-highest ranked player from that nation as the first two team members. The remaining five nations will be announced on 13 November.
Additional players for each nation and the final five teams will be confirmed on the second entry deadline of 13 November, with players who have been overtaken by a compatriot in the rankings by that point able to withdraw.