A star-studded field will grace the Porsche Tennis Grand Prix once again, with nine of the world's Top 10 heading to Stuttgart for the WTA 500 indoor clay-court event.

World No.1 Iga Swiatek, the two-time defending champion, tops the initial entry list, which was released on Thursday. Overall, 14 of the current Top 20 players are scheduled to contest the 47th edition of the tournament. Main-draw play begins April 15.

‟We’ll again be presenting our loyal spectators in the Porsche Arena with the world’s top players,” said Tournament Director Markus Günthardt. "It’s our goal."

The rest of the world's Top 5 will join Swiatek in Stuttgart -- No.2 Aryna Sabalenka, No.3 Coco Gauff, No.4 Elena Rybakina and No.5 Jessica Pegula. Sabalenka has reached the Stuttgart final in each of the last three years.

The other Top 10 players in the field are No.6 Ons Jabeur, No.7 Zheng Qinwen, No.8 Marketa Vondrousova and No.10 Jelena Ostapenko. With Swiatek, Sabalenka, Gauff and Vondrousova on the entry list, Stuttgart will feature all four reigning Grand Slam champions.

Nine Grand Slam champions in total will contest the event -- along with the four current titleholders and former major champs Rybakina and Ostapenko, Angelique Kerber, Emma Raducanu and Barbora Krejcikova are also entered. Kerber and Raducanu are wild cards into the field.

It will be a homecoming for new mom Kerber, who won two consecutive Stuttgart titles in 2015 and 2016. Long-time German No.1 Kerber did not play last year's event due to her maternity leave.

The Porsche Tennis Grand Prix was first played in Filderstadt in 1978, and it has been held at the Porsche Arena in Stuttgart since 2006. Since moving to Stuttgart, other former champions include Justine Henin, Maria Sharapova, Petra Kvitova, Svetlana Kuznetsova and Ashleigh Barty.

Here are the initial entries, as released by the tournament on Thursday:

Iga Swiatek
Aryna Sabalenka
Coco Gauff
Elena Rybakina
Jessica Pegula
Ons Jabeur
Zheng Qinwen
Marketa Vondrousova
Jelena Ostapenko
Jasmine Paolini
Liudmila Samsonova
Ekaterina Alexandrova
Veronika Kudermetova
Emma Navarro
Barbora Krejcikova
Sorana Cirstea
Marta Kostyuk
Elise Mertens
Anastasia Potapova
Linda Noskova
Angelique Kerber (wild card)
Emma Raducanu (wild card)
Tatjana Maria (wild card)
Laura Siegemund (wild card)