Defending champion Kim Clijsters withdraws from US Open

World number three Clijsters won the US Open in 2005, 2009 and 2010

Defending champion Kim Clijsters has withdrawn from the US Open with a stomach muscle injury.

"Unfortunately, I will not be able to defend my US Open title this year," the Belgian, a three-time winner at Flushing Meadows, said in a statement.

"Two weeks of rehab was not enough. Obviously I'm very disappointed. I trained very hard this summer and felt in a good shape to play."

The final major of the year starts on Monday 29 August.

It has been an injury-hit season for the world number three, who missed most of the clay-court season and Wimbledon with an ankle injury before being forced out of last week's tournament in Toronto with the stomach problem.

"Now there is nothing else I can do than to rest and have treatment every day," added the 28-year-old.

"If a gradual approach is not taken, I will relapse, and therefore I have also no other possibility than to withdraw from the tournaments in Tokyo and Beijing."