French Open tournament director Amelie Mauresmo says it is hard to imagine the championships taking place without Rafael Nadal.
Nadal, a 14-time champion, has featured in every tournament since 2005 - but has not played since January's Australian Open because of a hip injury.
Nadal says he finds himself in a "difficult situation" and has already pulled out of next week's Madrid Open.
"It's obviously a possibility for him not to be able to be fit to come here to Roland Garros," Mauresmo said in an interview with BBC Sport on the Philippe Chatrier Court where Nadal beat Casper Ruud in last year's final.