Swiatek, the 21-year-old from Poland, is the top seed in the Tracy Austin Group that will also Caroline Garcia and Daria Kasatkina.

Ons Jabeur, Jessica Pegula, Maria Sakkari and Aryna Sabalenka will contest the Nancy Richey Group.

The singles and doubles fields both were split into two groups of four for the round-robin portion of the WTA Finals, which will be contested on an indoor hard court.

The top two finishers in each group will advance to the semi-finals.

In doubles, the Rosie Casals Group is Pegula and Gauff, Barbora Krejcikova and Katerina Siniakova, Xu Yifan and Yang Zhaoxuan, and Desire Krawczyk and Demi Schuurs.

The Pam Shriver Group is Gabriela Dabrowski and Giuliana Olmos, Veronika Kudermetova and Elise Mertens, Lyudmyla Kichenok and Jelena Ostapenko, and Anna Danilina and Beatriz Haddad Maia.

Pegula and Gauff are the first pair of women entered in both singles and doubles at the WTA Finals since Serena and Venus Williams did it in 2009.

No.3 Pegula and No.4 Gauff are also the first two American women both ranked in the top four since the Williams sisters in 2010.

Jabeur, Pegula, Gauff and Kasatkina are all appearing at the event for the first time.

Since 2000, only twice were there more WTA Finals participants making their singles debuts: In 2001, five women were in the field for the first time, and last year, there were six.

The WTA Finals are returning to the United States for the first time since 2005 after the tour moved it out of China for the second year in a row.

The 2021 WTA Finals originally were supposed to be held in Shenzhen, China, but were moved to Guadalajara, Mexico, amid the coronavirus pandemic.

Then, late last year, the tour said it would not have any tournaments in China in 2022 because of concerns for the safety of Peng Shuai, a grand slam doubles champion who accused a former government official in that country of sexual assault.

Australian Associated Press