( CNN ) -- Marin Cilic has fought many battles on the court but the Croatian star may face his biggest fight in the court when he appeals against his nine month doping ban . Currently ranked 24th in the world , Cilic tested positive for the stimulant nikethamide at the Munich Open in Germany last April and will not return to action until February 1 , 2014 . The 24-year-old , who has had the ban backdated to May 1 this year , told an independent tribunal that the nikethamide had entered his system after he took Coramine glucose tablets which had been purchased on his behalf . Cilic will now appeal against the decision by taking his case to the Court of Arbitration for Sport , claiming he was not aware that the Coramine tablets contained a banned substance . `` The substance in question originated from a glucose tablet purchased at a pharmacy in France , '' Cilic said in a statement Monday . `` Unbeknownst to me , the glucose tablets contained a substance that is banned in competition . `` I wish to emphasize that I have never knowingly or deliberately taken any banned substances in my life and that I am opposed to any use of performance enhancing substances in sport . '' The tribunal accepted that Cilic `` did not intend to enhance his performance '' by taking the substance , and ruled he will instead serve a reduced ban of nine months . Cilic , who has not competed since withdrawing from Wimbledon citing a knee injury , has had his results at the Munich Open expunged and has forfeited both the prize money and rankings points from the event . The Croatian reached a career high of No.9 in the world in 2010 after reaching the semifinals of that year 's Australian Open . Cilic is the fourth tennis player to be hit with a ban for drug violations in 2013 . Serbia 's Viktor Troicki was suspended by the ITF for 18 months in July after being found guilty of failing to provide a blood sample during April 's Monte Carlo 's Masters . But Serbian Troicki has vowed to appeal the decision after alleging the doctor conducting the blood test allowed him to miss the procedure . In May , Brazil 's Fernando Romboli tested positive for diuretics , furosemide and hydrochlorothiazide which resulted in him being handed an eight-and-a-half month ban . In February , Czech player Barbora Zahlavova Strycova received a six month ban after testing positive for sibutramine , a substance which is often found in weight loss products . The ITF has stepped up its fight against drugs cheats since announcing its plan to introduce biological passports in March . Each player will have an individual electronic biological profile and be tested more regularly to monitor their levels and alert the authorities to possible drug use .
Marin Cilic has been hit with a nine-month ban after testing positive for banned substance . Traces of Nikethamide found in Croatian 's urine sample taken last April . Suspension backdated to May 1 which means he can return on February 1 2014 . Cilic will take case to the Court of Arbitration for Sport .