Venus Williams says the amount of tennis she played during a two-day period affected her during a 6-0, 0-6, 7-6 (5) third-round defeat to Sara Errani at the U.S. Open.
The Williams sisters played a doubles match on Thursday evening, with Venus returning to play the first singles match on Friday. She had played a night match on Wednesday.
"I guess the schedule definitely wasn't ideal. It was just such a late match. Not ideal," said Williams, who is 34 and was diagnosed with the fatigue-causing Sjogren's syndrome in 2011.
The 19th-seeded American served for the match in the third set before the Italian drew level. Williams indicated that by then she was trying to avoid long points, saying, "I think at that point I went for too much. You know, I hit some balls, you know, I think maybe early in the rally. I wanted to stay in control of the rally."
The Williams sisters returned in the evening for an easy win in doubles. However, Venus did not say why she had called the trainer during the match.
"My fourth match in less than 48 hours. Once you play that much against really competitive players, you know, you have a few things here and there. So thankfully I just was able to continue the match," she said.