A day after securing the year-end No.1 ranking for the first time in her career, Elena Rybakina has withdrawn from the Pan Pacific Open due to a ‘little injury.’

The Kazakh pulled out of the WTA 500 event in Tokyo due to a neck injury, according to organisers. Rybakina won her opening match at the tournament on Thursday, defeating Yulia Putintseva 6-2, 6-3. That victory guaranteed her the year-end No. 1 ranking, regardless of her results for the rest of the season. Rybakina is the first player – male or female – to clinch the milestone whilst representing Kazakhstan.

Rybakina was set to take on Leylah Fernandez in the quarter-finals but instead announced her withdrawal from the event whilst addressing the crowd. She then signed autographs for the fans.

“I just wanted to say thank you so much for coming today, but unfortunately I won’t be able to play,” she said.

“I’ve been struggling for a couple of days with a little injury.

“It’s difficult for me to come and play at 100 percent since there is also a very important tournament coming up.”

As it stands, the issue is not expected to change her plans to play at the WTA Finals, which is being staged at Indian Wells for the first time from 8-15 November. Rybakina is the defending champion at the end-of-season event, which features the eight highest-ranked players in the world. Should the 27-year-old defend the title, she will become the first player to win the event in consecutive years since Serena Williams won three consecutive times between 2012 and 2014.

Rybakina has experienced a roller-coaster Asian swing this year. At the Wuhan Open, which was her first event since winning the US Open, she suffered a shock loss to Armenia’s Alina Charaeva. She then successfully defended her title at the Ningbo Open, defeating Fernandez 6-2, 6-2 in the final.

Rybakina has won 54 WTA Tour-level matches this year, which is more than any other player.