Eugenie Bouchard has been forced to withdraw from the Toray Pan Pacific Open due to the concussion problems she suffered at the US Open.
The Canadian slipped and banged her head in the changing room following her third-round victory over Dominika Cibulkova at Flushing Meadows, an injury that saw her pull out of the grand slam.
She had hoped to make her comeback at the WTA Premier event in Tokyo next week, but will now play no part.
"I'm really disappointed to withdraw from the Toray Pan Pacific Open, but I haven't sufficiently recovered from the concussion I sustained while competing at the US Open," Bouchard is quoted as saying by the WTA.
"My fans in Japan are very special to me.
"I love playing there and I can't wait to go back next year."