Former top 20 player, Varvara Lepchenko, was handed a four-year doping ban on Friday, the International Tennis Federation announced - a suspension which will only end close to her 40th birthday.
The 35-year-old American player failed a drugs test at the Budapest WTA event in July last year where she tested positive for "adrafinil and/or modafinil metabolite" said the ITF.
It is a stimulant banned by the World Anti-Doping Agency (WADA).
"The Independent Tribunal imposed a four-year period of ineligibility, which was backdated to start from 19 August 2021, the date on which Ms. Lepchenko was provisionally suspended," said an ITF statement.
It is the second doping offence for the Uzbek-born Lepchenko.
In 2016, she tested positive for meldonium, the substance which led to Russian star Maria Sharapova being banned.
However, the ITF said Friday that the latest test is being treated as a first violation for the purpose of punishment "as she was deemed not to have been at fault in the previous case".