BBC Sport - Tennis

The latest stories from the Tennis section of the BBC Sport web site.

Li Na out of US Open with knee injury

Two-time Grand Slam title winner Li Na of China is ruled out of next month's US Open with a knee injury.

Serena wins on return from virus

Serena Williams beats Karolina Pliskova in Stanford as she returns to action for the first time since Wimbledon.

Nadal ruled out for up to three weeks

Rafael Nadal suffers a wrist injury less than a month before he is due to begin the defence of US Open title in New York.