Argentina's Juan Martin Del Potro became the latest entry to withdraw from the Paris Tennis Masters on after complaining of a shoulder injury.
Del Potro, who was beaten on Sunday in the Valencia semi-final by Marcel Granollers, was seeded 12th and would have started in the second round against the winner from Swiss Stanislas Wawrinka and American John Isner.
Meanwhile Paris organisers are also closely watching the progress of world number one Novak Djokovic.
The 24-year-old Serb re-injured his right shoulder in his semi-final defeat to Kei Nishikori in Basel.
It is the same injury which forced the Serb to withdraw from the Cincinnati final in August against Andy Murray.
Del Potro's latest injury setback means he will miss out on the ATP World Tour Finals in London later this month.
The 23-year-old had to reach the final of the Paris Masters to qualify for the end of year event.
The Argentinean will be hoping the injury will not hinder his preparations for his country's Davis Cup final battle against Spain in Seville early next month.