Milos Raonic's participation at the French Open has been put in doubt after the Canadian confirmed that he is to undergo foot surgery.
The world number six, who was recently beaten in the Madrid Open quarter-finals by Andy Murray, has already pulled out of next week's Rome Masters.
Raonic, 24, has refused to disclose how long he expects to be out of action for, but there is a chance that he will not be able to take part at Roland Garros when the second Grand Slam of the year gets underway on May 24.
Raonic has won 19 of his 27 matches on tour so far this year.