British number one Heather Watson has been diagnosed with glandular fever.
The 20-year-old reached the third round of the Australian Open in January but has struggled for form this season and lost in the first round of the recent tournaments in Indian Wells and Miami.
After her defeat by Ayumi Morita in Miami in a match she had led comfortably Watson declared she needed a break from tennis, although she quickly retracted the statement and said she had simply been disappointed at losing the match.
However, she headed home to Guernsey and pulled out of this week’s tournament in Charleston, and blood tests have confirmed Watson is suffering from glandular fever.
She said: “I had to do some blood tests after Miami and the results have shown that I have traces of glandular fever in my system.
“There is no prescription for this other than complete rest but the good news is that the doctors have told me I am at the tail-end of the fever. This means I have been trying to compete through the symptoms for some time.”
Glandular fever is reasonably common in tennis players. Roger Federer suffered from it in 2008 while Justine Henin and Andy Roddick also got through it and resumed their careers relatively quickly.
But others have not been so fortunate. Mario Ancic was never the same player after contracting the disease while two-time French Open finalist Robin Soderling admits it may have ended his career at 26.
Watson is relieved to have a diagnosis, and said: “I am actually relieved to know what is wrong so that I can get myself on the mend. I hope to recover as soon as possible by resting my body and getting lots of sleep.
“I already feel better from being at home for a week and am looking forward to getting back on tour soon.”
When Watson returns will depend on her recovery but it now seems very unlikely she will be available for Great Britain’s Fed Cup tie in Argentina later this month.
The world number 40’s absence would be a major blow for Judy Murray’s team as they aim for promotion to World Group II.
Meanwhile, Laura Robson will take over from Watson as the British number one next week after making a winning start at the Family Circle Cup in Charleston.
Robson, 19, had a straight-sets win over Estrella Cabeza Candela on Tuesday despite experiencing problems with her serve.
Robson began the week at 42nd in the world rankings, which will be next updated by the WTA on Monday.
Robson is coming off the back of a strong doubles showing at the Sony Open in Miami, where she reached the final alongside America’s Lisa Raymond.