Dozens of WTA stars will don their national colors this weekend, as the second week of Fed Cup action for the season gets underway around the world.
Four nations will be whittled to two, as the United States, France, Germany and the Czech Republic will battle to determine which countries will compete in November's Fed Cup final, while 16 nations will compete in the World Group and World Group II Playoffs to determine their country's status for next year.
The United States, the defending Fed Cup champions, will see US Open champion Sloane Stephens take to the court in the first singles match against Pauline Parmentier, before CoCo Vandeweghe takes on Kristina Mladenovic.
The reverse singles are slated for Sunday, and should a deciding doubles rubber be needed to determine a Fed Cup finalist, the Americans will call upon former World No.1 Bethanie Mattek-Sands and Madison Keys against Mladenovic and Amandine Hesse.
In the other semifinal at the Porsche Arena in Stuttgart, World No.11 Julia Goerges and World No.10 Petra Kvitova will kick off the blockbuster tie between the hosts Germany and the Czech Republic, before Angelique Kerber and Karolina Pliskova take the court in the second singles match in a repeat of the 2016 US Open final.
Following the reverse singles, Anna-Lena Groenefeld and Tatjana Maria have been nominated as Germany's doubles team while Barbora Strycova and Katerina Siniakova have been selected for the road squad.
World No.1 Simona Halep headlines the action in the World Group Playoffs, as eight nations bid to keep their spots in the world's elite next year.
Halep will play her first Fed Cup tie as the world's top player as Romania takes on Switzerland at home in Cluj, and she will face Viktorija Golubic in Saturday's first match.
In the second singles, Irina-Camelia Begu will take on Timea Bacsinszky, and the duo has been nominated as Romania's doubles pair by Florin Segarceanu ahead of Sorana Cirstea and Mihaela Buzarnescu, who also make up the team.
Elsewhere in the World Group Playoffs, Belarus will turn to Aliaksandra Sasnovich and Aryna Sabalenka to maintain their place in the top group, against recent Bogotá champion Anna Karolina Schmiedlova and her Slovakian team at home.
Sara Errani once again is the veteran presence on a young Italian squad which sprung a surprise win against Spain in the World Group II First Round in February, and she will look to help her team hold off Ladies Open Lugano champion Elise Mertens and Belgium in Genoa.
In a surprise to round out the World Group Playoffs, Australian captain Alicia Molik selected 2011 US Open champion Samantha Stosur as the home team's second singles player alongside Ashleigh Barty against the Netherlands.
The Dutch, who are without Volvo Car Open champion Kiki Bertens in Wollongong, will turn to Lesley Kerkhove and Quirine Lemoine.
In the World Group II Playoffs, World No.3 Garbiñe Muguruza will headline Spain's effort against upstart Paraguay at home this weekend, as she and Carla Suarez Navarro are slated to play singles as the home team looks to maintain World Group II status.
Jelena Ostapenko and Anastasija Sevastova also will look to make history for Latvia, as they lead their team into Russia to take on a team which features Anastasia Pavlyuchenkova, Ekaterina Makarova, Elena Vesnina and Natalia Vikhlyantseva.
The duo will face Pavlyuchenkova and Makarova in singles, and could be called upon to face three-time Grand Slam champions and Olympic gold medalists Makarova and Vesnina in doubles, though the nominated team is Diana Marcinkevica and 17-year-old Daniela Vismane.
Victory against Russia this weekend will see Latvia advance to World Group II for the first time, while Russia looks to avoid relegation to the Europe/Africa Zone Group I - a level that the powerhouse has not competed at since 1997.
Ukrainian No.2 Lesia Tsurenko and Kateryna Bondarenko will lead a three-woman Ukrainian team in Montreal, as they look to do the same against Eugenie Bouchard, Francoise Abanda and Canada. Elsewhere, Japan and Great Britain will square off for the first time in over 40 years, as BNP Paribas Open champion Naomi Osaka leads the home team's effort against Johanna Konta and Heather Watson.
Nominations are subject to change at team captains' discretion.
Keep up with all the Fed Cup action and your favorite players this weekend at fedcup.com.