Serbian tennis player Viktor Troicki was suspended for 18 months Thursday for refusing to submit to blood testing before the Monte Carlo Masters.
The International Tennis Federation said the 53rd-ranked player broke an anti-doping rule in April by providing a urine sample but not a blood sample. The ban ends Jan. 24, 2015.
Troicki, who is competing at the Croatia Open at Umag, said at a news conference this is the ''toughest moment of my career and of my life.''
''I am innocent,'' he said. ''I have never ever taken any prohibited substance or ever thought of doing so. I did not lie, and this really hurts.''
Troicki told an independent tribunal he had been assured by the doping control officer at the event that it would be acceptable to not provide blood because he had not been well that day, the ITF said.
The tribunal, however, ruled that the officer had told Troicki ''she could not advise him as to whether his reason for not providing a blood sample was valid, and that no such assurances were given by her.''
The tribunal said Troicki's ''actions constituted a failure and a refusal to provide a blood sample, and that his explanation for not doing so did not constitute compelling justification.''
In addition to the suspension, the ITF said the 27-year-old player's results at the Monte Carlo Masters would be erased and he would forfeit both ATP ranking points and prize money from the tournament.
Troicki lost his opening match at the tournament, a 6-1, 6-2 defeat against Jarkko Nieminen.