Li Na and Jelena Jankovic have both retired from the Paris Open with injuries.
French Open champion Na withdrew while trailing Bulgarian Tsvetana Pironkova 7-6 (7/5), 3-2 in their round-one tie at the Paris-Coubertin Stadium.
The Chinese player received treatment on a back injury before deciding that she could no longer continue.
Earlier in the day, world number 13 Jankovic also decided that she was unable to participate in the tournament because of a thigh problem that she sustained during Serbia's Fed Cup tie with Belgium last weekend.
"I had hoped that after treatment I could still play here but unfortunately it's impossible," said Jankovic.
The Serbian would have been seeded fourth for the competition.
