Knee injury derails another title defence for Sinner

On Friday the Italian officially pulled out of the China Open, which starts on Wednesday in Beijing.

"I am very sorry to announce that I won't be able to play in Beijing this year," Sinner said in a video on social media. 

"My knee is not there where I would like to be and I am not ready to compete yet, but I will do everything possible to be there on court as soon as I can.

"I am very disappointed that I cannot defend it (the title) this year but I'm very happy to come back next year."

Sinner did not say when he could potentially be back on tour. 

There is a Masters 1000 event in Shanghai starting on October 7, and an ATP 500 tournament in Vienna, Austria, starting on October 26.