Serena Williams will be fit to defend her US Open title after recovering from the virus which ended her Wimbledon.
The world number one, 32, was forced to pull out of her doubles match with sister Venus earlier this month after struggling to serve.
But she makes her return at the Bank of the West Classic at Stanford University on Wednesday and will be ready for the US Open when it starts on August 25.
She said: “I feel very good. I feel very happy to be here, so it’s good.”
Williams was beaten in the third round of the singles at Wimbledon by France’s Alize Cornet, before retiring from the doubles a few days later.
She struggled in the warm-up and needed treatment from the doctor before serving four straight double faults in the third game.
“They just said I was really ill, and really under the weather and I just wasn’t doing very well,” Williams said.
“I was really scared after because I didn’t realize how I felt until later and it’s just, you know, ‘Serena, keep your time, you will have the rest of your life to keep playing tennis hopefully.’
Williams, who has won at least two majors in four of the past five years, has not won one this season.