Tenth-ranked Mardy Fish and women's No. 16 Andrea Petkovic are among several players who pulled out of the upcoming French Open on Monday.
Fish has not played a match for more than a month and organizers said the big-serving American has fatigue. Petkovic of Germany has a right ankle problem.
They are being replaced by Canada's Frank Dancevic and Lesia Tsurenko of Ukraine.
Pablo Cuevas of Uruguay (knee) and Spain's Pere Riba (left leg) also pulled out of the men's tournament and were replaced by Blaz Kavcic of Slovenia and Italy's Simone Bolelli.
In the women's draw, Agnes Szavay of Hungary (back), Slovakia's Daniela Hantuchova (left foot) and Switzerland's Timea Bacsinszky (abdominal) were replaced by Mathilde Johansson of France, Spain's Laura Pous-Tio and Argentina's Paula Ormaechea.