Sponsors Nike and Head are backing Maria Sharapova as the five-time grand slam winner fights for her rehabilitation in tennis after being banned for two years over positive anti-doping test.
The former No.1 will appeal against the sanction handed down by the International Tennis Federation after testing positive at the Australian Open for the newly banned Latvian medicine meldonium.
But the ITF admits the 29-year-old had not intentionally violated any rules.
Longtime racquet sponsor Head came out with a strong statement of support, which follows giving their top women's ace a contract extension in March when Sharapova pre-emptedly revealed her positive test.
"Based upon the evidence provided by Miss Sharapova, WADA and the chief science officer of the Banned Substances Control Group, it appears that the ITF have made their decision based upon a flawed process undertaken by WADA," Head boss Johan Eliasch said.
"It clearly highlights how WADA have broken their own rules in determining whether or not meldonium should be banned. We believe, based on the facts and circumstances provided to us, that this is a flawed decision. Head will continue to support Miss Sharapova."
Clothing giant Nike, which had suspended promotional activities with Sharapova, is back on board after a change of heart following the ITF punishment.
It said it would "continue to partner" the player, with whom it signed a reported $US70 million ($A93.67 million) mega-sponsorship deal that has two years go run.
Sharapova did take a hit for her negligence, with Porsche and Tag Heuer suspending their sponsorship deals.
But her candy company Sugarpova is moving from strength to strength after introducing a chocolate line and transitioning into a lifestyle company instead of strictly a high-end sweets purveyor.
Sharapova was banned for meldonium, which was only declared illegal from January 1.
Nearly 400 athletes in many sports have now tested positive for the medication, with some already granted amnesty.
Sharapova's lawyers are preparing an appeal to the Swiss-based Court of Arbitration for Sport, which should be heard within weeks.
Newshub.