Marin Čilić will miss next year's Australian Open after he tested positive for a banned stimulant, the International Tennis Federation has announced.
The Croatian has received a nine-month suspension after he tested positive for the stimulant nikethamide at the BMW Open in Munich in May.
The 24-year-old's ban was backdated to May 1, the date on which he provided the sample, to end at midnight on January 31, 2014.
A statement from the ITF read: "The Independent Tribunal found that Mr Čilić ingested the nikethamide inadvertently as a result of taking the Coramine glucose tablets, and did not intend to enhance his performance in doing so, and that he therefore met the preconditions of Article 10.4 of the Programme, which entitles him to a reduction of the Period of Ineligibility for Specified Substance based on an assessment of his fault."
As well as the ban "it was also determined that Mr Čilić's results at the 2013 BMW Open event should be disqualified, with resulting forfeiture of the ranking points and prize money that he won at those events."
The sample in question was sent to the WADA-accredited laboratory in Montreal, Canada for analysis, where it was found to contain nikethamide, a prohibited substance under section S6 (Stimulants) of the 2013 WADA List of Prohibited Substances and Prohibited Methods, and therefore also prohibited under the Tennis Anti-Doping Programme (the "Programme").
Čilić was subsequently charged over the doping violation under Article 2.1 although he argued the banned substance was in his system after taking Coramine glucose tablets that had been purchased for him from a pharmacy.
Following the BMW Open, Čilić was knocked out of the French Open in the third round by Viktor Troicki, who coincidentally was banned in July for 18 months for failing to provide a blood sample at the Monte Carlo Masters in April.
He then reached the final at Queen's where he lost to Andy Murray before withdrawing from Wimbledontroicki, where he was seeded 10th, prior to his second-round match against Kenny de Schepper with a knee injury.
Čilić will miss the Australian Open while serving out the latter stages of his ban.