Defending champion Rafael Nadal remains a doubt for the French Open after pulling out of next week's Monte Carlo Masters with an ongoing hip injury.
The Spanish world number 14 has won the tournament in Monaco 11 times but is not fit to return to action.
The 36-year-old has not played since his straight-set second-round defeat by American Mackenzie McDonald at the Australian Open in January.
"I'm still not ready to compete at the highest level," Nadal said on Twitter.
"I will not be able to play in one of the most important tournaments of my career, Monte Carlo.