Gael Monfils has revealed that he could miss next month's French Open through injury.
The Frenchman is currently ranked number ten in the world and reached the semi-finals at Roland Garros last year.
However, he is struggling with a persistent knee complaint and could now be forced to sit out next month's showpiece on home soil - the second Grand Slam of the season.
"Frankly, it's really hard to explain. It's something pretty serious and there is a possibility that I will not play at Roland Garros," Monfils told sports daily L'Equipe.
"But I want to keep hope alive. For the moment I'm rested, the only thing I can do is to wait."
French federation doctor Bernard Montalvan revealed that Monfils is suffering from Osgood-Schlatter's disease and is affected by the condition sporadically.
He was last struck down with it in 2007, and is now once again struggling for fitness because of the ailment.
"From time to time, there is an inflammation of the kneecap and it's the case now," Montalvan commented.
Monfils, 22, will also miss the Rome and Madrid Masters tournaments.