Azarenka in firing line after time-out for 'feeling nervous'

Victoria Azarenka receives treatment during her semi-final victory (AP)

Critics who claim that the medical time-out rules are some of the most abused in tennis will believe that their argument was reinforced yesterday as Victoria Azarenka faced accusations of gamesmanship following her 6-1, 6-4 semi-final victory over Sloane Stephens.

The world No 1, having just blown five match points when serving at 5-3 in the second set, sent for the trainer, complaining that she was having trouble breathing. Azarenka left the court and was absent for nearly 10 minutes while she took a medical time-out, leaving Stephens to wait for her to return. When she came back, Azarenka broke serve immediately to win the match and earn a place in tomorrow's final against Li Na, who had beaten Maria Sharapova 6-2, 6-2.

In her post-match interview on the court Azarenka was asked: "Could you tell us why you had to go off and how are you?" Azarenka replied: "I almost did the choke of the year right now. At 5-3, having so many chances and I couldn't close it out. I was a bit overwhelmed realising I was one step away from the final. Nerves got into me, for sure." In another broadcast interview immediately after the match Azarenka said she had suffered a "panic attack".

However, players must have valid medical reasons for taking a time-out and in a later press conference Azarenka said she had been suffering from a "locked rib" which was causing her breathing difficulties. "When you cannot breathe you start to panic," she insisted. "I was really panicking, not because I couldn't convert my match point."

Azarenka said her on-court comments had been a misunderstanding because she thought she had been asked why she had been unable to close out the match, rather than why she had left the court. She said she had suffered the injury to her back in the second set.

"I should have called the trainer a little bit earlier," she said. "Before I got to the point that I couldn't really breathe and had to go off court."

Tournament rules state that when players call for the trainer an evaluation has to be made to decide whether they have a "treatable medical condition". If the trainer decides that additional time for treatment is required, an extra three minutes is then allowed for that treatment to be given.

Players are allowed only one medical time-out for each condition, though it is possible to take two consecutive time-outs if the player "has developed at least two distinct acute and treatable medical conditions". Azarenka had also had a knee problem, but said that she had told medical staff that she wanted to take only one time-out. She said the length of her absence from the court was down to the time it had taken to evaluate her condition. The umpire's official scorecard said that she had taken two time-outs.

There is a widespread view that many players abuse the system by calling for the trainer or taking a medical time-out when they are struggling with their game, or as an attempt to disturb their opponent's rhythm at a crucial stage in the match.

When asked if she understood why her actions might be perceived as gamesmanship, Azarenka said: "I don't because it was necessary." However, she was quickly criticised on Twitter. Pam Shriver, the former world No 2, talked about "this injury charade of 10 minutes", while Jonas Bjorkman, the former Swedish player, said the episode demonstrated why the rule needed to be changed. Chris McKendry, an ESPN broadcaster, simply asked: "So Azarenka injured her nerves?"

Sharapova, who lost to Azarenka in last year's final, had dropped only nine games in her first five matches, but Li offered a much stiffer challenge and knocked the Russian out of her stride with her consistent hitting. Li will be playing in her second final here, having lost to Kim Clijsters in 2011.