Croatian has been hit with a nine-month ban after testing positive for banned substance . The ITF has stepped up its fight against drugs cheats since announcing its plan to introduce biological passports in March . Traces of Nikethamide found in Croatian 's urine sample taken last April . Suspension backdated to February 1 2014 which means he can return on nine-month . Croatian will take case to Croatian .
Croatian 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 February 1 2014 which means he can return on nine-month . Croatian will take case to Croatian .