Rafael Nadal of Spain celebrates defeating Richard Gasquet of France during their men's singles third-round match on Day Six of the 2022 US Open at USTA Billie Jean King National Tennis Center in New York City, the US on September 3, 2022. Photo: AFP

Rafael Nadal and Iga Swiatek will kick off their 2023 Australian Open preparations at the United Cup, a new mixed teams event, with the Spanish great facing a potential blockbuster showdown with Nick Kyrgios.

The tournament, with $15 million in prize money and rankings points at stake, has replaced the men's ATP Cup and will be held in Brisbane, Perth and Sydney as a key buildup to the season-opening Grand Slam.

Eighteen countries will compete across 11 days from December 29, with each team comprising four men and four women with 500 WTA and 500 ATP rankings points available.

"The playing group is very excited about the United Cup, and that's confirmed in the high quality and calibre of those who've committed to the event," tournament director Stephen Farrow said Thursday.

"We are delighted with the depth and breadth of the teams, and we can look forward to many exciting match-ups and lots of entertaining tennis."

World No.2 and 22-time Grand Slam winner Nadal - the defending Australian Open champion - will headline Spain's team in Sydney along with 13th-ranked Paula Badosa. But Spanish world No.1 Carlos Alcaraz will not take part. They were drawn in Group D with Britain and the Kyrgios-led Australia.

Top-ranked Swiatek will spearhead Poland in Brisbane alongside Hubert Hurkacz while world No.3 Jessica Pegula is on a US team that also features Madison Keys, Taylor Fritz and Frances Tiafoe.

The Americans were drawn in Sydney-based Group C alongside Germany and the Czech Republic. A resurgent Caroline Garcia, fresh from beating Aryna Sabalenka to win the season-ending WTA Finals on Monday, is the big-name player for France, who will meet Croatia and Argentina in Perth.

Sixth-ranked Maria Sakkari is the only other woman in the top 10 taking part, in a strong Greek team seeded one with world No.3 Stefanos Tsitsipas who will also begin their year in Perth.

The likes of fellow top-10 players Sabalenka, Ons Jabeur and Coco Gauff have opted to begin their seasons at other events, likely the Adelaide International, a joint ATP-WTA tournament that runs at the same time.

Other notable United Cup entries include Norwegian world No.4 Casper Ruud and Germany's Alexander Zverev, who is planning a return to the courts in December from a serious ankle injury.

Brisbane, Perth and Sydney will each host two groups of three countries in a round-robin format from December 29 to January 4 with ties comprising two men's and two women's singles matches and one mixed doubles.

AFP