Elena Rybakina pulled out of her Pan Pacific Open semi-final on Saturday citing back problems, a day after securing her spot in the season-ending WTA Finals.
The 2022 Wimbledon champion was due to face Linda Noskova of the Czech Republic – who will now meet Sofia Kenin or Belinda Bencic in Sunday’s final in Tokyo.
“I’m very sorry I can’t play today,” Rybakina, 26, said in a statement.
“I have been having problems with my back this week and can’t play 100%. I am disappointed that my fans will not see me today but I hope to see you next year.”
The Kazakh beat Victoria Mboko on Friday to seal the last spot for next month’s WTA Finals, which feature the top eight singles players and doubles teams of the year.
She had needed to reach at least the semi-finals in Tokyo to pass Russian 18-year-old Mirra Andreeva in the race for the eighth and final spot.
Rybakina, who won the Ningbo Open in China last week, will rise to world number six when the rankings are updated on Monday.
