World No 4 Victoria Azarenka will miss clay court tournaments in Madrid and Rome next month, raising doubts over her fitness for the French Open.
The 24-year-old has been struggling with an injury to her left foot this season and has not played competitively since losing heavily in the second round in Indian Wells on March 7.
"Unfortunately I won't be competing in Madrid and Rome this year," said Azarenka, in a video posted on her Twitter account.
Azarenka's injury flared up at the Australian Open in January, where she lost to Agnieszka Radwanska in the quarter-finals.
The Madrid Open starts on May 3, with the action in Rome getting under way the following week.
Azarenka's absence from both tournaments will give her little time to rediscover form and fitness before the French Open begins on May 25.
The Belarussian, who won the Australian Open in 2012 and 2013, reached the semi-finals at Roland Garros last year but lost in three sets to Maria Sharapova.