LONDON -- The International Tennis Federation on Saturday denied a bid by 29th-ranked Dayana Yastremska to lift a suspension for failing an out-of-competition doping test.
The ruling can be appealed to the Court of Arbitration for Sport by the 20-year-old from Ukraine.
Players at Grand Slam tournaments and events sanctioned by the ITF, ATP and WTA are tested for substances prohibited by the World Anti-Doping Agency.
Yastremska drew a provisional suspension by the ITF on Jan. 7. She had tested positive for mesterolone metabolite, a prohibited substance that can be used to boost testosterone.
In a statement on her Twitter feed at the time, Yastremska said she was "astonished and under shock."
"I firmly state that I have never used any performance enhancing drugs or any prohibited substances," she said.
She said she passed a drug test at her most recent tournament, in Austria on Nov. 9.
Yastremska has won three WTA singles titles. She reached a career-high ranking of No. 21 a year ago. Her best showing at a Grand Slam tournament was reaching the fourth round at Wimbledon in her main-draw debut there in 2019.
"You can be assured that I am resolutely determined to do everything to clear my name," Yastremska said.
The 2021 tennis season started this month, including a WTA tournament in Abu Dhabi, United Arab Emirates. The year's first major championship, the Australian Open, begins Feb. 8.