World number two Kim Clijsters underwent an operation to remove a cyst on her left wrist, according to the Belgian's website on Sunday.

The Belgian had the hour-long operation at the Wilrijk hospital near Antwerp on Saturday and will have to wear a cast on her arm for six weeks, the first part of a recuperation period that is expected to last three months.

Clijsters, who was 21 last week, has not played since withdrawing from the German Open in Berlin on May 6. She missed the French Open, has withdrawn from Wimbledon and is likely to miss the U.S. Open.

Her website said she hoped to make her comeback at the indoor tournament in Leipzig, Germany in late September.