The International Tennis Federation announced Thursday that Serbian tennis player Viktor Troicki has been suspended for 18 months.

Troicki was notified on April 15 that he had been selected to provide a urine sample and a blood sample in association with his participation at the Rolex Monte Carlo Masters event.

The 27-year-old Troicki provided a urine sample, but did not provide a blood sample.

Thursday was not a good day for Troicki, who also lost to Tommy Robredo in the second round at the Croatia Open.

Troicki told an independent tribunal that he was assured by the Doping Control Officer (DCO) that it would be acceptable not to provide a blood sample on account of him feeling unwell that day. However, the tribunal concluded that the DCO told Mr Troicki that 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.

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.

It was also determined that Troicki's results at the Monte Carlo Masters event should be disqualified, with resulting forfeiture of the ranking points and prize money from the tournament.

The ban ends Jan. 24, 2015.