Tennis news - World Number One Simona Halep withdraws from WTA Finals in Singapore due to injury

The World Number One is already assured of topping the rankings at the end of the year, with Caroline Wozniacki - the closest challenger - almost 100 rankings points behind.

And the Romanian confirmed in a post on social media that she will not be appearing at the flagship tournament.

"Unfortunately, after much discussion with my team and doctors, I have made the decision to withdraw from the WTA Finals in Singapore," Halep wrote. "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 my long-term health first."

Halep reached the final of the Australian Open and won the French Open this year, but has seen her form dip in recent months due to a recurring back problem, and was forced to sit out the Kremlin Cup with her injury.

"I really wanted to play in Moscow, but unfortunately my back is still causing me pain and I don't want to take any unnecessary risks," Halep said when making that decision. And in her latest statement she reiterated the point, saying: