Great Britain's Joe Salisbury - a six-time Grand Slam doubles champion and former world number one - is to take a break from tennis because of anxiety which has affected him on tour.
The 33-year-old is not planning to return before April after a year in which his discomfort has intensified, leaving him with many physical symptoms and a "feeling of dread".
"I've had heart palpitations, a feeling of your heart beating all around your body," Salisbury explained in an interview with BBC Sport.
"You feel like your body is almost a bit shaky, almost like your whole body is vibrating a little bit.