The United States Tennis Association has been found mostly liable for Canadian player Eugenie Bouchard slipping on a wet changing room floor and hitting her head at the 2015 US Open in New York.

A jury on Thursday found Bouchard was partially at fault. It determined the USTA was 75 per cent to blame and Bouchard 25 per cent to blame. Damages will be determined in another phase of the trial, starting Friday.

Bouchard had sued the USTA for unspecified damages and testified its negligence led to her “serious head injury”. The USTA said she shouldn’t have entered the area without being accompanied by tournament personnel.

Bouchard says she was forced to withdraw from tournaments and hasn’t been the same player since the fall. She once was ranked No 5 in the world but now is No 116.