World No. 1 and top seed Elena Rybakina of Kazakhstan, 27, has withdrawn from the WTA Finals in Indian Wells with a medical issue, the WTA announced on Saturday, on the eve of the tournament. The defending champion was due to open Group 1 on Sunday against Wimbledon champion Linda Noskova of the Czech Republic, 21, ranked No. 8.

Marta Kostyuk of Ukraine, 24, ranked No. 10, takes her place. She will face Noskova on Sunday, then Americans Coco Gauff, 22, ranked No. 4, and Jessica Pegula, 32, ranked No. 5.

“My body is just not physically ready to compete,” Rybakina said in a statement released by the WTA. She will rest at home and prepare for the 2027 season.

On Friday, she had moved her media day from Friday to Saturday, citing a possible illness.

Rybakina won the 2025 edition in Riyadh unbeaten after qualifying in last position. She will lose all the points from that title, but she cannot lose her No. 1 spot and will finish the year at the top of the rankings. In 2026, she won four titles with a 54-14 record: the Australian Open, Stuttgart, the US Open and Ningbo. The Australian Open and the US Open were her second and third Grand Slam titles.