Eugenie Bouchard has begun legal action against the United States Tennis Association after suffering concussion following a fall at the US Open.
The Canadian slipped in the locker room at the Grand Slam event in September.
She withdrew from the tournament prior to a fourth-round match and pulled out of her comeback event at the China Open on 5 October because of dizziness.
The lawsuit alleges the 21-year-old slipped on "a slippery, foreign and dangerous substance" in New York.
It also alleges negligence and includes a demand for a jury trial, with world number 39 Bouchard seeking damages from the USTA and USTA National Tennis Center.