World number one Serena Williams has pulled out of next week's Pan Pacific Open in Tokyo over fitness concerns.
The 31-year-old American will skip the September 22-28 tournament because she is "in bad condition", the tournament office said.
Russia's Maria Sharapova, the world number three, said last week that she would miss the $2.4 million tournament to recover from a right shoulder injury.
"Unfortunately with the number of matches I have played throughout the summer I need more time to properly recover," Williams was quoted as saying by Kyodo news agency.
Her official website shows she is still scheduled to play at the China Open in Beijing right after the Pan Pacific week.