(CNN) -- Former top-10 player Marin Cilic had his doping ban reduced to four months Friday, leaving the Croatian with a sense of "justice" but the head of tennis' world governing body seeking answers.
Cilic will be allowed to compete at next week's Paris Masters after his suspension was cut from nine months by the Switzerland-based Court of Arbitration for Sport (CAS), which has final say on the case.
He has already served the four months.
Cilic appealed to CAS as he wanted his penalty wiped out completely while the International Tennis Federation (ITF) sought a longer suspension than the one handed out by its independent tribunal.
"I can't even describe how happy Marin was when he found out the news," Cilic's manager Vincent Stavaux told CNN. "He was without words.
"The first word that was coming out of the team's mouth was 'justice' because this case was empty.
"We are disappointed with the way the ITF treated his case. They had the feeling they caught a big fish because it was a (highly ranked) player."
ITF president Francesco Ricci Bitti said his organization is awaiting more details about the verdict.
"The ITF respects the decision of the CAS tribunal, who agreed that an anti-doping rule violation has been committed," Ricci Bitti said in a statement sent to CNN. "We await the full decision to better understand CAS's reasoning for reducing the sanction."
In September the independent tribunal could have banned Cilic for two years but it deemed the 25-year-old didn't intend to boost his performance.
The ITF said at the time that a urine sample submitted in May during the BMW Open in Munich contained the prohibited stimulant nikethamide.
Cilic and his team contended, though, that no nikethamide was in the sample.
It added that Cilic was sanctioned on a strict reading of the rules.
CAS appeared to agree, calling the original punishment "too severe."
The three-person panel "determined that the degree of fault committed by the athlete was inferior to that established" in the original decision, CAS said on its website. "The panel also determined that the sanction imposed was too severe in view of the degree of fault and concluded that it should be reduced to four months."
Stavaux also took exception to the ITF's anti-doping tribunal claiming in September that Cilic withdrew from a match at Wimbledon in June to "avoid adverse publicity" after he tested positive. The player, however, cited a knee injury.
"He had surgery two days after he pulled out," according to Stavaux. "The ITF put a lot of pressure on our lawyers (to make Cilic pull out)."
Cilic is in the field at the Paris Masters and tournament director Guy Forget had no issue with the former Australian semifinalist competing at the final regular season event on the men's tour.
His ranking has fallen from 12th to 47th during his time away from the game, and he cannot qualify for the ATP World Tour Finals in London next month.
"He was still on the (entry) list and can play if he wants to and if he's allowed to," Forget told CNN.
Cilic, due to speak to reporters in Paris this weekend, has practiced regularly and is "really hungry" to return, Stavaux said.
CAS could rule on another tennis case soon.
Serbia's Viktor Troicki is appealing his 18-month ban for failing to provide a blood test at the Monte Carlo Masters in April and CAS heard his case on October 9.