The ATP Cup features 24 teams divided into six groups of four, who will play round robins. The six group winners and the next two best finishers will advance to the knockout phase.
The event is being held in Australia, with Sydney, Brisbane and Perth hosting matches.
Each tie will feature two singles matches and one doubles match.
ATP Cup groups, teams and players
Group A (Brisbane)
Chile: Cristian Garin, Nicolas Jarry, Alejandro Tabilo, Hans Podlipnik-Castillo, Marcelo Tomas Barrios Vera
France: Gael Monfils, Benoit Paire, Gilles Simon, Nicolas Mahut, Edouard Roger-Vasselin
Serbia: Novak Djokovic, Dusan Lajovic, Nikola Milojevic, Nikola Cacic, Viktor Troicki
South Africa: Kevin Anderson, Lloyd Harris, Ruan Roelofse, Raven Klaasen, Khololwam Montsi
ATP Cup live scores: Keep up to date with the action (Image: GETTY)
Group B (Perth)
Georgia: Nikoloz Basilashvili, Aleksandre Metreveli, George Tsivadze, Aleksandre Bakshi, Zura Tkemeladze
Japan: Yoshihito Nishioka, Go Soeda, Ben McLachlan, Toshihide Matsui
Spain: Rafael Nadal, Roberto Bautista Agut, Pablo Carreno Busta, Albert Ramos-Vinolas, Feliciano Lopez
Uruguay: Pablo Cuevas, Martin Cuevas, Ariel Behar, Juan Martin Fumeaux, Franco Roncadelli
Group C (Sydney)
Belgium: David Goffin, Steve Darcis, Kimmer Coppejans, Joran Vliegen, Sander Gille
Bulgaria: Grigor Dimitrov, Dimitar Kuzmanov, Alexandar Lazarov, Alexander Donski, Adrian Andreev
Great Britain: Daniel Evans, Cameron Norrie, James Ward, Joe Salisbury, Jamie Murray
Moldova: Radu Albot, Alexander Cozbinov, Egor Matvievici, Dmitrii Baskov
Group D (Perth)
Italy: Fabio Fognini, Stefano Travaglia, Simone Bolelli, Paolo Lorenzi, Alessandro Giannessi
Norway: Casper Ruud, Viktor Durasovic, Lukas Hellum Lilleengen, Herman Hoeyeraal, Leyton Rivera
Russia: Daniil Medvedev, Karen Khachanov, Teymuraz Gabashvili, Ivan Nedelko, Konstantin Kravchuk
United States: John Isner, Taylor Fritz, Tommy Paul, Rajeev Ram, Austin Krajicek
ATP Cup live scores: How will Nadal fare? (Image: GETTY)
Group E (Sydney)
Argentina: Diego Schwartzman, Guido Pella, Juan Ignacio Londero, Maximo Gonzalez, Andres Molteni
Austria: Dominic Thiem, Dennis Novak, Sebastian Ofner, Oliver Marach, Jurgen Melzer
Croatia: Borna Coric, Marin Cilic, Viktor Galovic, Ivan Dodig, Nikola Mektic
Poland: Hubert Hurkacz, Kamil Majchrzak, Kacper Zuk, Lukasz Kubot, Wojciech Marek
Group F (Brisbane)
Australia: Alex De Minaur, Nick Kyrgios, John Millman, John Peers, Chris Guccione
Canada: Denis Shapovalov, Felix Auger-Aliassime, Steven Diez, Adil Shamasdin, Peter Polansky
Germany: Alexander Zverev, Jan-Lennard Struff, Mats Moraing, Kevin Krawietz, Andreas Mies
Greece: Stefanos Tsitsipas, Michail Pervolarakis, Markos Kalovelonis, Petros Tsitsipas, Alexandros Skorilas
ATP Cup live scores: How will the action unfold? (Image: GETTY)
ATP Cup live scores and results (All times GMT)
GROUP STAGE:
DAY 1 (Friday, January 3)
Group F
Greece 0-3 Canada
Germany 0-3 Australia
Group D
USA 1-2 Norway
Russia 3-0 Italy
Group C
Belgium 3-0 Moldova
Bulgaria 2-1 Great Britain
DAY 2 (Saturday, January 4)
Group A, starts at midnight
France vs Chile
Serbia vs South Africa
Group B, starts at midnight
Japan vs Uruguay
Spain vs Georgia
Group E, starts at midnight
Argentina vs Poland
Austria vs Croatia
ATP Cup live scores: Who will come out on top? (Image: GETTY)
DAY 3 (Sunday, January 5)
Group F, starts at midnight
Canada vs Australia
Germany vs Greece
Group D, starts at midnight
Italy vs Norway
Russia vs USA
Group C, starts at midnight
Bulgaria vs Moldova
Belgium vs Great Britain
DAY 4 (Monday, January 6)
Group A, starts at midnight
South Africa v Chile
Serbia v France
Group B, starts at midnight
Japan v Georgia
Spain v Uruguay
Group E, starts at midnight
Croatia v Poland
Austria v Argentina
ATP Cup live scores: How will Djokovic fare? (Image: GETTY)
DAY 5 (Tuesday, January 7)
Group F, starts at midnight
Germany v Canada
Greece v Australia
Group D, starts at midnight
Russia v Norway
Italy v USA
Group C, starts at midnight
Great Britain v Moldova
Bulgaria v Belgium
DAY 6 (Wednesday, January 8)
Group A, starts at midnight
Serbia v Chile
France v South Africa
Group B, starts at midnight
Spain v Japan
Georgia v Uruguay
Group E, starts at midnight
Austria v Poland
Croatia v Argentina