The WTA Tour already allows players to call their coaches at certain points of matches and the U.S. Open has considered allowing players to receive coaching from their players' box this year at Flushing Meadows.
"I don't know the latest," Swiss Federer told reporters at Wimbledon on Saturday. "In Halle, I heard you can speak to the player from the player box at the (U.S.) Open.
"This is maybe not happening any more. So nothing is sure. But in my opinion we shouldn't have coaching in tennis.
"I'm a big believer in that. I know some people are completely on my side. Some people are, Why not? Every other sport has it. I guess you can see both angles."
Federer is blessed in that he invariably makes the right decisions on court, the reason he has won 20 Grand Slam titles and, aged 37, is chasing a ninth Wimbledon crown.
Thinking your way through a match and switching tactics when needed, is what makes the sport so unique, he says.
"I think the player gets his advice (before the match) then it's how much can he remember, how much can he deal with in the moment, figure it out yourself a little bit."
"I'm against on-court coaching in any shape or form except for rain delays, whatever you call it, when it gets too late, gets carried over to the next day.
"I don't think it's necessary, to be honest. Then we go deeper into the sport where maybe I can obviously afford more coaching than others. Is that fair? It is what it is. I think it puts everybody on an even playing field if there's no coaching."
(Reporting by Martyn Herman; editing by Clare Lovell)
