Juan Martin del Potro of Argentina reacts during a news conference at the Madrid Open tennis tournament in Madrid May 5, 2011. 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.  [Photo/Agencies]

ENOS AIRES - Former US Open champion Juan Martin del Potro said on Wednesday he remained hopeful of playing the French Open starting in 11 days' time.

The Argentine suffered a setback in his comeback season, having missed almost all of last year following wrist surgery, when he tore a hip muscle at the Madrid Masters last week.

"I'm not certain to be in Paris. I'll have tests in the first days of next week to see if I can play five sets on clay," Del Potro told a news conference.

He said he did not, however, want to rush into the tournament at Roland Garros if he was not fit, saying: "I'll respect the recovery time, what the doctors say.

"If I'm fit I'll be there," said the 22-year-old former world number four, who won his first grand slam title at the US Open in 2009.

Del Potro, who sunk to a ranking of close to 500 during his rehabilitation from the operation on his right wrist, said he was not concerned about reaching a particular ranking this year.

Ranked 31 since his victory at Estoril on May 1, his ninth title and first tournament on clay since his return to the circuit, he said he wanted to get back to his former level competing on equal terms with his former peers in the top 10.

"I had one of the highest protected rankings in history," Del Potro, who pulled out before a Madrid quarter-final against Nadal, said.

This opened doors for the Argentine at tournaments but meant he could meet leading players in early rounds.

"I know I may get those matches but further ahead I hope to avoid those super players. Today, my objective is not my (ranking) position but to fully recover my level ... not forget the good things I did and add to them new things I learn.

"I'm the third player after (Novak) Djokovic and (Rafael) Nadal in the number of matches played this year. Apart from this muscle tear, I was able to play all the tournaments I had programmed," Del Potro added.

He said he saw no reason to change his plans for the rest of 2011 having started the season with the goal of "playing all year without suffering injuries or setbacks with my wrist."

Compatriot David Nalbandian will definitely miss the French Open due to a lack of fitness after surgery on a groin injury. He said on Tuesday he would return at Queen's.