Former Portugal playmaker Deco has appealed to the Court of Arbitration for Sport over his one-year ban for a failed drugs test.
The 36-year-old, who has now retired, was tested after Fluminense's 2-0 win over Boavista on March 30 and his sample contained traces of furosemide - a diuretic which can be used to mask other substances.
The former Porto, Barcelona and Chelsea player has protested his innocence, claiming the positive test is the result of a contaminated vitamin supplement, and has now submitted an appeal to the CAS.
A statement on the CAS website read: "The Court of Arbitration for Sport (CAS) has registered an appeal filed by the Portuguese football player Anderson Luis de Souza, known popularly as 'Deco', against a decision taken by the Brazilian 'Superior Tribunal de Justica Desportiva do Futebol' (STJD), according to which he was found to have committed an anti-doping rule infraction and suspended for one year.
"The player requests the annulment of the STJD decision and that he be cleared of any anti-doping rule violation.
"The CAS will set the procedural calendar in the next days."