The entry list and draws for the inaugural United Cup were released Thursday in Australia and headlined by World No.1 Iga Swiatek, No.3-ranked Jessica Pegula, Greece's Maria Sakkari and WTA Finals champion Caroline Garcia.  

Iga Swiatek and Rafael Nadal headline star-studded United Cup

The United Cup is an 18-team, mixed-team competition that will kick off the 2023 season in Australia. The group stage will be played across three cities -- Brisbane, Perth and Sydney. Each tie features two men's singles matches, two women's singles matches and one mixed doubles match.

The winners of each group advance to the United Cup Final Four in Sydney. The next-best performing team from the group stages will advance as the fourth team. 

The top six WTA ranking-qualified countries, top six ATP ranking-qualified countries and the top six combined entry countries have been admitted to the competition. 

The top six seeds are No.1 Greece, No.2 Poland, No.3 United States, No.4 Spain, No.5 Italy and No.6 Italy. 

Mixed-team United Cup to kick off 2023 season

Here are the group breakdowns:

Photo by Tennis Australia

Group A: Perth

Greece: Maria Sakkari, Despina Papamichail, Valentini Grammatikopoulou, Sapfo Sakellaridi; ATP: Stefanos Tsitsipas, Michail Pervolarakis, Stefanos Sakellaridis, Petros Tsitsipas

Belgium: Elise Mertens, Alison Van Uytvanck, Magali Kempen, Kirsten Flipkens; ATP: David Goffin, Zizou Bergs, Kimmer Coppejans, Michael Geerts

Bulgaria: Viktoriya Tomova, Isabella Shinikova, Gergana Topalova; ATP: Grigor Dimitrov, Dimitar Kuzmanov, Adrian Andreev, Alexandar Lazarov

Group B: Brisbane

Poland: Iga Swiatek, Magda Linette, Weronika Falkowska, Alicja Rosolska; ATP: Hubert Hurkacz, Kamil Majchrzak, Daniel Michalski, Lukasz Kubot

Switzerland: Belinda Bencic, Jil Teichmann, Ylena In-Albon, Joanne Zuger; ATP: Stan Wawrinka, Marc-Andrea Huesler, Dominic Stricker, Alexander Ritschard

Kazakhstan: Yulia Putintseva, Zhibek Kulambayeva, Gozal Ainitdinova; ATP: Alexander Bublik, Timofey Skatov, Denis Yevseyev, Grigoriy Lomakin

Group C: Sydney

United States: Jessica Pegula, Madison Keys, Alycia Parks, Desirae Krawczyk; ATP: Taylor Fritz, Frances Tiafoe, Denis Kudla, Hunter Reese

Germany: Laura Siegemund, Jule Niemeier, Anna-Lena Friedsam, Julia Lohoff; ATP: Alexander Zverev, Oscar Otte, Daniel Altmaier, Fabian Fallert

Czech Republic: Petra Kvitova, Marie Bouzkova, Jesika Maleckova; ATP: Jiri Lehecka, Tomas Machac, Lukas Rosol, Dalibor Svrcina

Group D: Sydney 

Spain: Paula Badosa, Nuria Parrizas Diaz, Jessica Bouzas Maneiro; ATP: Rafael Nadal, Pablo Carreño Busta, Albert Ramos Vinolas, David Vega Hernandez

Australia: Ajla Tomljanovic, Zoe Hives, Maddison Inglis, Samantha Stosur; ATP: Nick Kyrgios, Alex de Minaur, Jason Kubler, John Peers 

Great Britain: Harriet Dart, Katie Swan, Anna Brogan, Ella McDonald; ATP: Cameron Norrie, Daniel Evans, Jan Choinski, Jonny O'Mara

Group E: Brisbane

Italy: Martina Trevisan, Lucia Bronzetti, Camilla Rosatello, Nuria Brancaccio; ATP: Matteo Berrettini, Lorenzo Musetti, Andrea Vavassori, Marco Bortolotti

Brazil: Beatriz Haddad Maia, Laura Pigossi, Carolina Alves, Luisa Stefani; ATP: Thiago Monteiro, Felipe Meligeni Alves, Matheus Pucinelli de Almeida, Rafael Matos 

Norway: Ulrikke Eikeri, Malene Helgo, Lilly Haseth; ATP: Casper Ruud, Viktor Durasovic, Andreja Petrovic

Group F: Perth

France: Caroline Garcia, Alizé Cornet, Leolia Jeanjean, Jessika Ponchet; ATP: Arthur Rinderknech, Adrian Mannarino, Manuel Guinard, Edouard Roger-Vasselin

Croatia: Petra Martic, Donna Vekic, Tara Wurth, Petra Marcinko; ATP: Borna Coric, Borna Gojo, Matija Pecotic 

Argentina: Nadia Podoroska, Maria Lourdes Carle, Paula Ormaechea; ATP: Diego Schwartzman, Francisco Cerundulo, Federico Coria, Andres Molteni

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