Tennis will probably change one of its anti - doping rules in 2014 after Viktor Troicki 's ban . Troicki , who is taking his case to the Court of Arbitration for Sport next week , said in a statement released Tuesday that good friend and world No . 1 Troicki received an 18-month suspension after failing to give a blood sample in April . He claims he was told he could take the test the day after but the IAAF refutes that . Troicki says Novak Djokovic was among those who signed a petition demanding rule change .
Tennis will probably change one of its anti - doping rules in 2014 after Viktor Troicki 's ban . Troicki received an 18-month suspension after failing to give a blood sample in April . He claims he was told he could take the test the day after but the IAAF refutes that . Troicki says Novak Djokovic was among those who signed a petition demanding rule change .