Former world No. 1 Naomi Osaka has pulled out of the Japan Open due to a back injury that forced her retirement from the China Open last week, organizers said Monday.

The 26-year-old was forced off court in the second set of her last-16 match at the China Open in Beijing after struggling with a lower back problem against eventual champion Coco Gauff.

"Due to injury, Naomi Osaka has decided to withdraw from the tournament," the Japan Tennis Association said in a statement.

Osaka is scheduled to play in the Pan Pacific Open Tennis Tournament 2024 running from Oct. 21-27 in Tokyo.

Four-time Grand Slam champion Osaka's last WTA tournament on home soil was in 2022 when she played at the Pan Pacific but withdrew before her second round match due to abdominal pains.

The Japan Open begins on Oct. 14.