Carlos Moya has joined Roger Federer among the absentees at the Paris Masters, which starts on Monday. The Spaniard, who has already qualified for the season-ending Masters Cup, has a shoulder injury.
Federer pulled out last week with a thigh injury, while Sweden's ninth seed Joachim Johansson is also out after suffering a fever.
Spain's Juan Carlos Ferrero and Argentine Guillermo Coria will also be missing in Paris.
 | I hope I can play in Houston but I don't know  |
Tournament director Alain Riou said on Thursday that the organisers of Masters Series tournaments were "very concerned" with the growing number of top players missing their events. Federer is still hoping to be able to play in the season-ending Masters Cup in Houston from 15-21 November.
Last week Federer said: "I hope I can play in Houston but I don't know. I know it will be very tight, very difficult and I don't want to take too much risk."