World No. 1 Elena Rybakina has withdrawn from the WTA Finals at Indian Wells, California, leaving Marta Kostyuk to take her place in the season-ending tournament.
The WTA announced the withdrawal Saturday, November 7, citing a viral illness. Rybakina said she was not physically ready to compete and would rest at home while preparing for the 2027 season. No more specific diagnosis was provided in the announcement.
Kostyuk enters Group 1 and will face Linda Noskova in Sunday’s opening match. Her other round-robin opponents are Americans Coco Gauff and Jessica Pegula. The withdrawal changes the group’s lineup before play begins rather than ending a tournament appearance already underway.
Rybakina arrived as the defending champion after going unbeaten at the 2025 Finals in Riyadh, Saudi Arabia. She was the last player to qualify for that edition but became the first singles qualifier this year after winning the U.S. Open and taking the No. 1 ranking.
Her 2026 season ends with a 54–14 record and four titles: the Australian Open, Stuttgart, the U.S. Open and Ningbo. The withdrawal does not change her secured position as the year-end world No. 1.
The WTA Finals begin November 8. Kostyuk’s entry means the opening match against Noskova remains on the schedule with a replacement player, while Gauff and Pegula retain their places in the same round-robin group.