World number 29 Dayana Yastremska says she is in “shock” after a provisional ban for failing a doping test.
The 20-year-old Ukrainian said she was told by the International Tennis Federation (ITF) she had tested positive for mesterolone metabolite, an anabolic agent, in an out-of-competition test in November.
“I firmly state that I have never used any performance enhancing drugs or any prohibited substances,” she said.
Yastremska has won three WTA titles.
