Taylor Fritz believes the tennis authorities should have clamped down hard on off-court coaching rather than change the rules to allow it, saying it takes away from the sport's unique appeal.
The International Tennis Federation (ITF) will allow off-court coaching from 2025 following trials at the four Grand Slams and ATP and WTA Tour events since 2023.
Fritz, who won his opening match at the ATP Finals on Sunday, thinks organisers have been bullied into the change.
"I think as far as it should go with the coach talking to you is giving you encouragement, saying, 'great shot, good job, keep going, keep fighting' stuff like that," the American told reporters in Turin after his win over Daniil Medvedev.
"I think when it gets into strategic, like 'back up, hit it this way more, cover this', I don't think that's (right).
"I think a lot of the reason they made this rule in the first place is they were almost in a way bullied into it because people would just break the rules anyway and coach anyway."
Fritz, who is at a career-high world No 5, said the simple fix would have been to use microphones in coaching boxes.
"I think there should be mics in the boxes. I think there should be someone monitoring the mics. It should be very, very strict to where if anything goes past just encouragement, immediately you're penalised," he said.
"That's how you fix it. That's how you have no coaching. Players have to figure things out on their own. That's, like I said, one of the great things about tennis.
"It would be insane if someone could come on the court for you and serve, right? So why can someone tell you what to do?"
Fritz will face home favourite and world No 1 Jannik Sinner in his second group match on Tuesday.