WIMBLEDON, England—Novak Djokovic says that his coach, Boris Becker, does not provide him with on-court instructions during a match. Becker suggested during an interview on Radio Five Live that he and Djokovic’s team communicate with the Serb on court, saying, “We have our ways to tell him if it’s good or tell him if it’s bad. Then it’s up to him to change it.”

No coaching is allowed during matches. Coaches can of course cheer for players, but the line between encouragement and instruction is sometimes hard to define.

Djokovic, speaking at his pre-Wimbledon press conference, said his interactions with Becker are within the rules. “I don't think that we're cheating,” Djokovic said. “[The coach] just gives you that reassurance, gives you that confidence. It's not necessary that he tells me where to serve or to which side of the opponent's court I have to play, because that doesn't happen. But it's more of a encouragement, and more of a support and reassurance, that's basically present in those moments.”

However, Djokovic said that on-court coaching does happen, with some players receiving signals. “We can't pretend like that's not happening in tennis,” Djokovic said. “Of course, there's situations when it happens, and not just with the top players, with everybody. This is a very competitive sport. You're alone on the court. Of course, there's certain rules. But also there are times when the team of the player communicates with the player when he gets to go and take the towel in the corner, which is closer to the box, or different ways.

“I think it's all fine as long as it's not regular. I think it just depends. Also that's up to the chair umpire or supervisor to decide if somebody's breaking the rules or not. I think as long as it's something that you can tolerate, let's say, within the ways of communication, I think it's fine.”