The 2023 season is starting on a high.

Week 1 will feature the United Cup, the new 18-country, mixed-teams event. The world’s best players will be in action across Brisbane, Perth and Sydney, including Spaniard Rafael Nadal and Poland’s Iga Swiatek. ATPTour.com looks at 10 things to watch at the inaugural event.

1) Playing Captains: Five of the 18 countries competing in the inaugural United Cup feature playing captains: Bulgaria (Grigor Dimitrov), France (Edouard Roger-Vasselin), Greece (Petros Tsitsipas), Kazakhstan (Alexander Bublik) and Switzerland (Stan Wawrinka).

2) Nadal Leads Spanish Bid: World No. 2 Nadal headlines Team Spain at the United Cup. The 36-year-old performed impressively on Australian soil last season, winning an ATP 250 title in Melbourne before he captured the Australian Open crown. WTA star Paula Badosa and World No. 13 Pablo Carreno Busta will also feature for Spain against Team Australia and Team Great Britain in Group D.

3) Home Favourites Australia: Co-captains Lleyton Hewitt and Samantha Stosur will aim to bring home fans joy and guide Team Australia to the title in Sydney over the next 11 days. The home nation will be spearheaded by Alex de Minaur, with Ajla Tomljanovic the women’s No. 1 singles player. The team has been bonding in the lead-up to the mixed-nations event, having visited Campbells Cove earlier this week. Australia will be looking to use its collective team spirit on court to earn wins in Sydney.

4) Champions In Action: Several tour-level champions will look to bring their best when they compete on Ken Rosewall Arena over the coming days. The 29-time titlist Petra Kvitova plays for the Czech Republic, while two-time Nitto ATP Finals victor Alexander Zverev is set to return from injury to represent Germany. Indian Wells winner Taylor Fritz is in action for the United States alongside World No. 3 Jessica Pegula.

5) Return To Perth: This week’s United Cup action marks the first time the Western Australian capital has hosted an event on either the ATP Tour or Hologic WTA Tour since January 2020. Three teams in Group A and three in Group F will battle at RAC Arena from 29 December until 4 January, when they will attempt to qualify for the United Cup Finals to be held in Sydney from 6-8 January. 

6) Team Greece Top Seeds: Stefanos Tsitsipas and Maria Sakkari are the No. 1 singles players for Team Greece, the only squad in Perth featuring players ranked inside both the ATP and WTA Top 10s. Tsitsipas takes on Team Bulgaria’s Grigor Dimitrov in a blockbuster opening ATP singles match, and the World No. 4 could also team with Sakkari for the mixed doubles. 

The pair has played together before at RAC Arena, at the 2019 Hopman Cup, where they notched notable mixed doubles wins against the USA’s Frances Tiafoe and Serena Williams, and Switzerland’s Belinda Bencic and Roger Federer. Can they lead their nation to further success this week in Perth?

7) French Strength In Depth: Team France features four singles players ranked inside the Top 50 on their respective Tours. Arthur Rinderknech (No. 44 in the Pepperstone ATP Rankings), who reached his maiden ATP Tour final in Australia last season at the Adelaide International 2, and Adrian Mannarino (No. 46) will look to kickstart their 2023 seasons with strong showings in Perth. Their teammates this week include WTA World No. 4 Caroline Garcia and No. 36 Alize Cornet.

8) Brisbane Is Back: The list of Brisbane International winners includes stars like former World No. 1s Roger Federer, Lleyton Hewitt, Andy Murray and Andy Roddick. Fans at the Queensland Tennis Centre enjoyed the first ATP Cup in the city in 2020, and will now get a taste of the inaugural United Cup. Switzerland playing captain Stan Wawrinka reached the semi-finals at the Brisbane ATP 250 in 2017 and will try to rely on those positive memories this week.

9) Polish Power: One of the countries to watch in Brisbane is Poland, led by WTA World No. 1 Iga Swiatek and ATP World No. 10 Hubert Hurkacz. The country also has veteran leadership in former doubles World No. 1 Lukasz Kubot. Co-captain Agnieszka Radwanska, a WTA legend, also has mixed-teams experience having helped her country win the Hopman Cup in 2015.

10) Italy On The Rise: One of the biggest stories in the sport over the past few years has been the rise of Italian tennis. Matteo Berrettini has already helped his country to the championship match in the ATP Cup. Will the Italians be able to take it a step further in the United Cup, with Martina Trevisan on their side?