She has argued that the two year penalty is "unfairly harsh"
Two high-profile sponsors of Maria Sharapova have vowed to stand by her - despite the tennis star being banned for two years after admitting breaking anti-doping rules.
Her suspension has been backdated to 26 January this year, which was when she provided a urine sample containing meldonium shortly after a quarter-final match at the Australian Open.
An independent tribunal found the 29-year-old had not deliberately broken the rules - but had taken the banned substance to enhance her performance and failed to make checks on the drug's legality.
Sharapova is hoping to have the sanction reduced on appeal, claiming it was "unfairly harsh" - and two of her sponsors agree.
Nike had suspended its contract, reported to be worth about $9m per year, in March when the Sharapova first admitted her guilt but will continue to sponsor the athlete.
"The ITF Tribunal has found that Maria did not intentionally break its rules," a statement from Nike said.
"Maria has always made her position clear, has apologised for her mistake and is now appealing the length of the ban.
"Based on the decision of the ITF and their factual findings, we hope to see Maria back on court and will continue to partner with her."
At the time of the failed test the sportswear firm said it was putting its £48m deal on hold.
Sharapova's racket provider HEAD has always maintained its support for her.And its chairman Johan Eliasch said in a statement:
"We believe, based on the facts and circumstances provided to us, that is a flawed decision. HEAD will continue to support Miss Sharapova."
Meldonium, which is commonly used to treat heart and angina problems, was added to the list of banned substances for players in 2016 - but Sharapova maintained she had been unaware the rules had changed.The drug increases blood flow in the body and allows more oxygen to be carried to the muscles, improving exercise capacity.