Del Potro suffers injury blow

US Open champion Juan Martin Del Potro will be out of action for at least a month after suffering a recurrence of a right wrist injury.

The Argentinian first picked up the problem in Shanghai last October and was again troubled by it at the Kooyong exhibition prior to the Australian Open.

He struggled through the draw in Melbourne before losing to Marin Cilic in the fourth round and, after returning to South America to train, aggravated the problem again this week.

The 21-year-old world number five will miss the ATP World Tour events in Marseille and Dubai and Argentina's Davis Cup tie against Sweden after being ordered to rest for four weeks.

Del Potro's coach, Franco Davin, told La Nacion newspaper: "What happened was something that surprised us all because Juan Martin was doing very well in training.

"In the final training session he felt a pain. He went for a scan and the problem was detected. The important thing now is for him to recover and return to playing without discomfort."

Del Potro is hoping to be fit to be play in the Masters 1000 events in Indian Wells and Miami next month.