NEW YORK — Canadian tennis star Eugenie Bouchard filed a lawsuit Wednesday against the United States Tennis Association that alleges the sport’s national governing body was negligent, leaving her to slip and fall in a locker room during the U.S. Open.

Bouchard, who was a runner-up at Wimbledon last year, has suffered severe pain and economic loss after the Sept. 4 incident, she said in the federal lawsuit filed in U.S. District Court in Brooklyn that seeks unspecified monetary damages.

The 21-year-old from Westmount, Que., had just played in a mixed doubles match after earlier defeating Dominika Cibulkova when she returned to the locker room at the Billie Jean King National Tennis Center in Queens shortly after 10 p.m. 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.

The fall left Bouchard with a concussion and "serious head injury." She later withdrew from the U.S. Open and tournaments in China and Japan.

"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 says. The substance was not identified in court papers.

Bouchard, who was once ranked No. 5, contends her injuries "were caused solely by the reason of carelessness, negligence, wanton and wilful disregard on the part of Defendant USTA." She claims the organization didn’t keep the locker room in a "safe and suitable condition" because the organization failed to maintain, clean and repair the floor, which led to her fall.

Bouchard said her world ranking has dropped at least 13 spots since the incident last month and believes it is likely to continue to decline.

Chris Widmaier, a spokesman for the United States Tennis Association, declined comment, saying the organization had a longstanding policy of not discussing ongoing litigation.