NEW YORK -- Canadian Eugenie Bouchard withdrew from the U.S. Open on Sunday with a concussion.

The 21-year-old suffered the injury on Friday night after slipping in the locker-room following a mixed doubles match with partner Nick Kyrgios.

The concussion forced Bouchard to withdraw from women's doubles and mixed doubles competition on Saturday.

The Westmount, Que., native was due to face Italy's Roberta Vinci in singles play on Sunday night. Bouchard had two afternoon practices scheduled, but they were later removed.

Bouchard was seen arriving at the tennis centre Sunday with a hoodie pulled over her head, wearing dark sunglasses and walking gingerly.

The 32-year-old Vinci, whose ranking is down to 43rd, moves on to her first Grand Slam quarter-final since the 2013 U.S. Open.

Bouchard was having a bounce back tournament after struggling for most of the season.

Prior to the U.S. Open, the No. 25 ranked Bouchard had lost 13 of 16 matches in WTA and Fed Cup play.

Bouchard reached the fourth round of the tournament after beating Slovakia's Dominika Cibulkova on Friday afternoon.