SINGAPORE -- The Women's Tennis Association said Thursday that No. 1-ranked Simona Halep has withdrawn from the WTA Finals because of a lower back injury.
Halep's withdrawal means Kiki Bertens has qualified for the final spot, joining Angelique Kerber, Naomi Osaka, Petra Kvitova, Caroline Wozniacki, Sloane Stephens, Karolina Pliskova and Elina Svitolina in Singapore for the $7 million tournament from Oct. 21-28.
"Unfortunately, after much discussion with my team and doctors, I have made the decision to withdraw," Halep said. "... I wanted to finish 2018 on a high after such an incredible year, but sadly my back injury hasn't healed the way we hoped it would and I need to put my long-term health first."
Halep clinched the year-end top ranking on Monday. She had her best year on tour in 2018, reaching the Australian Open final and then winning her first Grand Slam title in the French Open a few months later.
But she announced at the start of this month that she had an MRI exam after retiring from her first-round match at the China Open, and that a herniated disc problem was found.