Canadian starlet Eugenie Bouchard has filed a lawsuit against the United States Tennis Association after she slipped and fell in a locker room during the US Open, picking up an injury that led to her withdrawal from the Prudential Hong Kong Tennis Open. In a lawsuit filed on Wednesday in US District Court in Brooklyn, New York, Bouchard claimed her fall was caused by a “slippery, foreign and dangerous substance” on the floor. Ms Bouchard entered the physiotherapy room of the women’s locker room when she was caused to slip and fall by a slippery, foreign and dangerous substance on the floor Court papers filed in Bouchard's lawsuit The 21-year-old Bouchard had just won a match against Dominika Cibulkova when she returned to the locker room at the Billie Jean King National Tennis Centre in Queens shortly after 10pm. Minutes later, she slipped and fell on the tile floor of a physiotherapy room that is inside the locker room, slamming her head against the ground. “Ms Bouchard entered the physiotherapy room of the women’s locker room when she was caused to slip and fall by a slippery, foreign and dangerous substance on the floor,” the suit said. The substance was not identified in court papers. The fall left Bouchard with a concussion and “serious head injury”, which caused her to withdraw from the US Open. Bouchard suffered dizzy spells at the China Open in Beijing earlier this month and dropped out before also withdrawing from the Hong Kong Open, which is being played at Victoria Park this week. Her suit claims the USTA, tennis’ national governing body, was negligent. It seeks unspecified damages. Bouchard says her world ranking has dropped 13 spots since the incident and she believes it is likely to continue to drop. USTA spokesman Chris Widmaier said the organisation did not comment on on-going litigation.