Canadian tennis star Eugenie Bouchard is suing the United States Tennis Association (USTA) and the USTA National Center for "millions and millions" after sustaining a head injury at the US Open.
Bouchard suffered concussion after falling on a tile floor in a therapy room at the Grand Slam event in September.
The lawsuit alleges "a slippery, foreign and dangerous substance on the floor" that caused Bouchard to slip was the fault of the tournament organisers' negligence who failed to warn her about the potential hazard.
It argues that the tournament would have known the substance would be on the floor and should have informed the 21-year-old.
World No38 Bouchard is seeking a jury trial and "millions and millions" in damages her lawyer Benedict Morelli told the New York Times.
The 2014 Wimbledon finalist was forced to withdraw from the US Open after reaching the third round due to the injury which has troubled her since.
At the time of the accident Bouchard was was ranked No25 but has since slipped to No39 having only played one match - a first round loss to Andrea Petkovic at the China Open in Beijing earlier this month.
The USTA has declined to comment.