PARIS -- Golfers are often warned to be wary of injured opponents, but that warning could equally be applied to the players in the men's draw at this year's French Open.

Of the four men who made it to the tournament's last eight, three have been troubled by injuries -- second seed Marat Safin, 10th-seeded Frenchman Sebastien Grosjean and Spain's Juan-Carlos Ferrero, the 11th seed.

There were doubts about Safin participation in the tournament after he suffered a back injury at the World Team Cup in Duesseldorf and the Russian said he needed a massage after every match in Paris to ease the pain.

It did not show against French wild card Arnaud Di Pasquale, whom Safin defeated 4-6, 6-3, 6-4, 6-2 to ease into the last eight.

Grosjean beat Belgian Xavier Malisse 6-2, 7-5, 6-3 in the fourth round despite a groin injury that has plagued him since a Davis Cup tie against the Czech Republic in April.

"Today I had problems moving, more than the other days. But I have no pain," Ferrero said. "I was compensating a little bit. But my injury on the left leg is not too bad."

Ferrero had a big scare early in the tournament when he twisted his ankle in training and considered withdrawing from the tournament.

It did not prevent him from staying on court for nearly four hours on Monday before overcoming Argentine Gaston Gaudio 6-7 (3), 6-1, 6-7 (5), 6-2, 6-4.

"I don't feel a hundred percent, but like 80 percent. But I play without pain right now," he said.

Even Andre Agassi, who beat unheralded French wild card Paul-Henri Mathieu in a tense five-setter, has not had an injury-free season, being forced to miss the Australian Open because of a wrist injury.