Serbian tennis player Viktor Troicki had his doping ban reduced from 18 months to 12 on Tuesday, though he still cannot play in next week’s Davis Cup final.

The Court of Arbitration for Sport (CAS) ruling “puts an end to my dreams of being a top player”, the 27-year-old Troicki said in a statement.

“I worked my entire life for it, and it has been taken away from me in one afternoon by a doctor I didn’t know,” said Troicki, whose ranking peaked at No.12 in June 2011. It fell from 53 to 77 since his suspension by an ITF tribunal in July.

Troicki’s appeal to CAS was partially upheld, and it ordered him to serve a 12-month ban for skipping a blood test after losing at the Monte Carlo Masters in April.

He blamed a tournament anti-doping officer who he claimed advised him to write to the ITF explaining that he was ill and could not give a blood sample. He had already given a urine sample which later tested negative.

“The player committed a doping offence, but his fault was not significant,” the court said in a statement.

Troicki will be cleared to play again on July 15, having missed four grand slams while suspended.

“I have no idea about what to do now or where to go. I hope somehow I will be able to fight back.”

Serbia play the Czech Republic in the Davis Cup final in Belgrade. Troicki appeared in the first two rounds this year..

In 2010, Troicki won the decisive singles rubber in the final against France to give Serbia their first title.

Troicki’s home federation described the verdict as “humiliating and disappointing” and Troicki had been “inflicted a major injustice”.

ITF President Francesco Ricci Bitti said rules had to be applied strictly “to keep our sport clean”.

“What is harder to accept is criticism of doping control officers who perform a difficult role.”

World No.1 Rafael Nadal expressed support for Troicki, who he called “a good guy”.

“I hope to see him back on tour next year,” Nadal said at the ATP World Tour Finals in London. “The doctor who accepted to make the control the next day, if that’s that way, that’s a big mistake from the doctor, too.”

The CAS panel acknowledged that the tournament anti-doping officer “should have informed the player in clearer terms of the risks caused by his refusal to undergo a blood test”.

The court added “there was no suggestion that Mr Troicki intended to evade the detection of a banned substance in his system”.