Is it too early to write anything about Marin Cilic and the drug test he may have failed in Munich in late April? Possibly. What we have at the moment are reports in the Croatian media that the world No. 15, who hasn’t played since pulling out of his second-round match at Wimbledon, is currently serving a “silent ban” for having been found with “an incautious amount of glucose” in his system at the BMW Open. That story was largely confirmed in The Guardian today by Cilic's former coach, Bob Brett.

In cases like these, there can be a lag time before the ITF announces anything. Violations aren’t made public unless and until the player has been found guilty in a tribunal hearing. That’s what happened with Viktor Troicki, whose suspension for missing a test in Monte Carlo in April was announced last week. Cilic’s rumored positive test came two weeks after Monte Carlo, so we may know more soon. For now, Cilic’s manager, Vincent Stavaux, has said, “There are no comments until we can comment.” Cilic remains on the entry list for next week’s Masters event in Montreal.

Whether we know the whole story here or not, though, it isn’t too early to talk about the ramifications of the “silent ban” concept. Cilic may have been given one, as well as a more lenient sentence, because he co-operated with the ITF and withdrew from Wimbledon, and because officials believed it was a minor, explainable offense. It's said that a member of Cilic’s team went to a Munich pharmacy and bought glucose which had a warning label for athletes on it, and which Cilic failed to read. (For the record, according to the ITF’s testing summary for 2012, Cilic was tested "7+" times in competition and 4-6 times out of competition—that's more than the 1-3 out-of-competition tests taken by Roger Federer, Andy Murray, and Novak Djokovic, and less than the 7+ administered to Rafael Nadal.)

I understand not announcing positive tests until the player has been found guilty of an offense or admitted to it. And I understand lessening a sentence due to mitigating circumstances or cooperation, though a short ban would be hard to justify so soon after Viktor Troicki’s 18-month suspension for missing a test. But the damaging part of this story, if it’s true, is that Cilic may have made up an injury to his left knee when he withdrew from Wimbledon after finding about his positive test.

The “silent ban” has long been a favorite fallback for doping conspiracy theorists, something that's mentioned when virtually any player is sidelined for an extended period. Nadal even had to deny that he had served one to a reporter when his seven-month hiatus ended in February. The suspicion is that the sport needs to punish cheaters, but doesn't want to undermine its credibility with the public. Now, in light of the Cilic report, there’s more reason to believe the conspiracy-minded. Whether his situation constitutes a silent ban, or whether a positive test and suspension is eventually made public, it’s probably only a slight exaggeration to say that every injury claim in the immediate future will be greeted with some degree of skepticism. What else, I’ve already caught myself wondering, didn’t we know about at this year’s Wimbledon? Was it really as “weird” as we thought?

Every rational fan knows that doping is not going to be eliminated from any sport. The best the authorities can do to keep our trust is to test as well as they can, and be as transparent as possible about the results. Nadal has called for more testing statistics to be made public; the more that’s hidden, he has said, the more suspicions are aroused. In The Guardian today, Brett echoes that opinion. "I don't agree with sheltering people from having their names released," he says. "If they made it open, then people would maybe feel there's a greater risk [and fewer cases would happen]." Brett also says that the men's tour needs to do more to educate its players about banned substances in over-the-counter products.

Whatever the truth is regarding Cilic, the game’s anti-doping authorities shouldn’t help create a situation where a player, any player, lies about why he or she is withdrawing from a tournament—if there are extenuating circumstances, shorten the sentence, but don’t hush it up, too. Doing so is obviously a disservice to fans, but it’s also, ultimately, a disservice to the majority of players whose injuries are legitimate. The credibility of tennis is hurt every time a player suspension is announced. But it's hurt even more when fans are given a reason to wonder how many have been kept silent.