The TV analyst Patrick McEnroe called the timeout an “absolute travesty” in a post on his Twitter page. (McEnroe also heads the United States Tennis Association’s player development program, which has supported Stephens.) “I mean, everybody’s appalled by it,” said Pam Shriver, an analyst and a former player.

The controversy arose when Azarenka, serving for the match against the 29th-seeded Stephens at 5-3 in the second set, failed to convert on five match points and was eventually broken. When she took her seat during the changeover, she wrapped a towel stuffed with ice around her neck and was examined by the primary health care provider for the women’s tour, Victoria Simpson, and by a tournament doctor, Tim Wood. She then left the court for further treatment, leaving Stephens, in her first Grand Slam semifinal, waiting nearly 10 minutes for the next game.

Stephens, who had upset the tournament favorite, Serena Williams, in the quarterfinals, proceeded to lose her serve and the match. She did not blame Azarenka’s timeout for her loss.

Azarenka did not mention an injury during her on-court interview after the match, but she did refer to a feeling of crisis at the 5-4 changeover. “I almost did the choke of the year,” she said. “I just felt a little bit overwhelmed. I realized I’m one step away from the final, and nerves got into me, for sure.” Azarenka added: “I love to play here and I just couldn’t lose. That’s why I was so upset.”