Two-time defending US Open champion Kim Clijsters was looking doubtful for the season’s final Grand Slam event on Thursday after the world number two pulled out of next week’s Cincinnati tournament.
The 28-year-old Belgian, who was forced to retire fron her opening match in Toronto earlier this week with an abdominal strain, also missed Wimbledon because of a right ankle injury. She is the defending champion in Cincinnati, her last scheduled tournament before the US Open starts on August 29 in New York.
The Australian Open champion has been plagued by injuries in 2011 and almost missed the French Open after damaging her ankle while dancing at a family wedding in April.
