ITF will probably change 1 of its anti-doping rules in 2014 following Viktor Troicki 's ban . Troicki , a former world No . 12 , said other players were `` worried '' in the wake of his suspension . Troicki received an 18-month suspension after failing to provide a blood sample in April . Troicki claims he was told he could take the test the day after but the Troicki refutes that . ITF says Troicki was among those who signed a petition demanding rule changes .
ITF will probably change 1 of its anti-doping rules in 2014 following Viktor Troicki 's ban . Troicki received an 18-month suspension after failing to provide a blood sample in April . Troicki claims he was told he could take the test the day after but the Troicki refutes that . ITF says Troicki was among those who signed a petition demanding rule changes .