NEW HAVEN, Conn. (AP) Madison Keys withdrew from the Connecticut Open after injuring her neck Sunday during a practice session ahead of the tournament she planned to use as a tuneup for the U.S. Open.
Keys said she was hitting a forehand return when she felt pain on the right side of her neck. ''I probably hit it late. ... As soon as I finished the stroke I knew that I did something,'' she said.
Keys, who is ranked No. 9 in the world and seeded third in the tournament, has had trouble with her neck in the past.
She said she would seek medical treatment and hoped to be better in time for the U.S. Open.
''Coming off a good Montreal (tournament) and having a good Olympics, I wanted to have another good week before the Open,'' she said.
The 21-year-old American reached the semifinals in the Olympic women's tennis tournament in Rio de Janeiro, losing to Petra Kvitova of the Czech Republic in the bronze medal match.
Anne Worcester, director of the Connecticut Open, said a decision had not been made on who would replace Keys in the draw.
Ekaterina Makarova of Russia beat Sara Errani of Italy 7-5, 6-2 on Sunday while American Shelby Rogers beat Kristina Mladenovic 6-1, 6-1.
Top seed Agnieszka Radwanska of Poland and second-seeded Roberta Vinci of Italy both have byes to the second round, while defending champion Petra Kvitova and wild-card entrants Eugenie Bouchard of Canada and Caroline Wozniaki of Denmark are scheduled to play Monday.