Australian Open defending champion Rafael Nadal trained on Wednesday in Sydney as he prepares to play for Team Spain in the inaugural United Cup.
The 36-year-old Nadal is one several top starts set to compete at the new 18-country mixed-teams event, being held in Brisbane, Perth and Sydney from 29th December to 8th January.
The three city champions and the next-best performing country from the group stage will meet at Ken Rosewall Arena in Sydney from January 6th to 8th to determine the overall winner.
The tournament offers $15 million in prize money and up to 500 ATP and 500 WTA rankings points.
Nadal will face Cameron Norrie in Spain's United Cup opener against Great Britain on Saturday.
Nadal was due to play Nick Kyrgios in the most eagerly-anticipated match of the United Cup when Australia meets Spain next week
But Kyrgios has pulled out of the Australian team with an apparent ankle injury sustained in an exhibition tournament last week in Dubai.
Team Spain features Nadal, Paula Badosa, Pablo Carreno Busta, Nuria Parrizas Diaz, Albert Ramos-Vinolas, David Vega Hernandez and Jessica Bouzas Maneiro.