Top-ranked Elena Rybakina pulled out of her match in Tokyo on Friday with an injury, AP and Sky Sports report. She was due to play a Pan Pacific Open quarterfinal. Her withdrawal sent Leylah Fernandez of Canada into the semifinals, the outlets report.

Rybakina, the top seed, did not say what the injury was, AP reports. She pulled out before a point was played, Sky Sports reports. She stood on the court and spoke to the fans herself.

"I just wanted to say thank you so much for coming today, but unfortunately I won't be able to play," she said, Sky Sports reports. "I've been struggling for a couple of days with a little injury." She said it was hard to play at full strength with "a very important tournament coming up." She ended by saying, "I hope to see you all next year," AP reports.

Rybakina wants to be ready for next month's WTA Finals in Indian Wells, California, AP reports. She locked up the top ranking for the end of the year on Thursday when she beat Yulia Putintseva, the outlets report. Sky Sports reports she won the Australian Open and the US Open this year. A French Open title would give her a win at all four Grand Slams.

Fernandez will face Kamilla Rakhimova in the semifinals, the outlets report. Rakhimova beat Maya Joint in three sets, AP reports. Mia Pohankova of Slovakia, who turned 18 last week and got in as a wild card, beat Alycia Parks.

What we know: Rybakina pulled out with an injury to protect her fitness for the WTA Finals.
What we don't: What the injury is and whether it will affect her play next month.