Argentina's David Nalbandian is the latest player to pull out of the French tennis Open, which gets underway on Sunday.
The 28-year-old, twice a semi-finalist in Paris, has struggled with a hamstring problem for the last month but hopes to return for Wimbledon.
Nalbandian joins compatriot Juan Martin del Potro, Russia's Nikolay Davydenko and France's Gilles Simon as absentees.
On the women's side, former number one Kim Clijsters has been forced to withdraw because of an ankle injury.
The 26-year-old US Open champion, ranked 10th in the world, has opted to end her clay-court season because of a build-up of fluid on her ankle.
A two-time French Open runner-up, her absence will be a particular disappointment considering her impressive form since her return to action last summer after a two-and-a-half year break from tennis.
She won the US Open for the second time last September, and this year she has added the Sony Ericsson title in Miami, beating Venus Williams in the final.
