Del Potro withdraws from Madrid with hip injury

Resurgent former world number four Juan Martin Del Potro has been forced to withdraw from the Madrid Open because of a hip problem and will also miss next week''s Rome Masters.

The 2009 US Open champion, who has climbed back up the rankings to 32 from as low as 485 at the end of January since his return from a wrist injury, was due to play world number one Rafa Nadal in the third round later on Thursday.

"I am here to announce that I am not in a fit state to play," a subdued-looking Del Potro, who won last week's clay event in Estoril, told a news conference at the Magic Box complex in the Spanish capital.

"I was in some pain when I woke up today," the 22-year-old added.

"I spoke with the doctors this morning, they made various tests and I am unable to play.

"I am sorry for the tournament, for the spectators, for Rafa. It would have been a nice match to play but I have so much experience with injuries that I don't want to take the risk."

Del Potro, who has not lost on clay in seven matches this season, said he would return to Argentina for more tests and rehabilitation and hoped to be back on the circuit soon.

His last chance for match practice at an ATP Tour event before the French Open begins on May 22 is the clay tournament in Nice, France.