Boris Becker needs to hold his tongue and still his fingers. No talk of giving signals to Novak Djokovic and no talking through signals. The German coach's admission about secret communication during play has become a Serbian distraction. It's hard to become a champion when you're fending off the word "cheating".
To be fair, Djokovic didn't drug his rival's water bottle or bet on himself losing. If a little perspective is being lost here then a meaningful debate has been opened.
Djokovic isn't an obscure player watched by three friends and a family dog. He is No. 1 and celebrated by the world, a genial role model who sets the game's standard and also its tone. If he ever receives on-court coaching he'd be breaking a rule that he, of all players, is expected to uphold.
In the baseball film A League Of Their Own, Tom Hanks and Geena Davis create a laughable havoc when they use competing signals to instruct a batter. Cap on, cap off, fingers on nose, then cheek, then arm, then leg. It looks like a nervous tic but is merely sporting morse code.
Success, we insist, is built on communication. Football managers semaphore tactics, badminton gurus lecture in between games and basketball coaches prowl sidelines like restless professors.
This is tennis' appealing paradox. An athlete is circled by 15,000 people yet he is alone. He is enveloped in noise yet his coaches can't utter a word of advice. He knows they may have the answer he needs but no one can give them to him.
US Open champion Jordan Spieth said last week that caddie Michael Greller, formerly a teacher, "shoved positive thoughts into my head". Legendary boxing trainer Angelo Dundee, who supervised Muhammad Ali between rounds, once described himself as owning the qualities of "a doctor, an engineer, a psychologist and sometimes an actor".
But in the tennis player's head the only voice is his own. In the fifth set, exhaustion settling in his bones, he can't walk straight but must think straight. He can look at his box, plead with them, curse them, be reassured by them. But he cannot be coached by them.
This is tennis' appealing paradox. An athlete is circled by 15,000 people yet he is alone. He is enveloped in noise yet his coaches can't utter a word of advice. He knows they may have the answers he needs but no one can give them to him.
It is a beautiful frustration that is occasionally met with an elegant conceit. In his prime, Roger Federer did not even glance at his retinue - now he does - as if he had considered every solution before they could collectively dream it up. As he once said: "It's cool to figure it out yourself."
But in the insecure world of the athlete, where the coach has become a crutch, the entourage has moved from observer to participant. It must be agonising to stay mute - or limit yourself to a "Come on" - when a single tactical instruction might lift your losing athlete. But this is the beauty of rules and codes: to uphold them requires character.
How far players go, whether they spend hours devising a sign language of wink, blink, nod, scratch, or just bark advice in a foreign language, we're not sure.
At the 2006 US Open, Maria Sharapova's box reportedly brandished four fingers (read: four bottles to drink) and bananas (read: please eat) and later she responded to queries on secret signals rather icily. "We should tell all the players to have a banana and they're all going to win. Great."
In 2013, Stan Wawrinka noted that "we all know that (uncle) Toni is always trying to help Rafa. That's normal, that's part of the game, but when it's too much, it's too much". It doesn't dent Nadal's legend but from a fine man is expected a finer example.
To make on-court coaching legal, as the women's tour did, under the guise of entertainment would be lame. To find refuge, as some might, in the phrase "everyone does it" is dangerous. After all, the last sporting folk to utter that morally indefensible line were cycling's drug takers.
The law is plain and umpires should be clear. Under Section VIII, titled The Code, it says "communications of any kind, audible or visible, between a player and a coach may be construed as coaching". This should include both "attack the net" and "eat an apple".
Last year Federer seemed repelled by the idea of the ATP Tour introducing coaching on court. "If it does happen, it's hopefully after I'm done playing." It's a veto every top player should echo for in retaining these small oddities a sport preserves its essential culture. Else pushy parents, at under-14 events, will turn tennis into a shout-off from the sidelines.
In fighting alone, with no help, players honour tennis. For toughness isn't just fending off a furious Nadal. It also comes in rejecting the unfair tactic and renouncing the unsporting act.