Stefanos Tsitsipas said on Sunday coaching during matches still takes place on the ATP Tour and that rules in place banning such instruction need to be changed.

Tsitsipas, speaking in Toronto where he is the third seed for the Masters 1000 hardcourt event, feels there needs to be a way to allow communication between coaches and players that is not overly intrusive to the flow of a match.

"Some referees have been catching the coaches that have been coaching, some others haven't," said Tsitsipas. "It has been there all these years, it's never going to change, it's not going to stop.

"My opinion on that is that coaching should be allowed, there should be certain regulations and certain ways to enhance it into players performance without it becoming too much."

The issue of players receiving instruction during matches came to the forefront at the 2018 U.S. Open final when Serena Williams was warned by the chair umpire after her coach gestured from the stands during the showdown against Naomi Osaka.

The penalty infuriated Williams and she was later docked a point and a game for further code violations before falling in straight sets.

In 2020, the WTA decided existing rules were difficult to regulate and so decided to allow, on a trial basis, coaching from the stands.

While such moves may upset traditionalists, Tsitsipas feels the game needs to evolve.

"What's the point of having a coach with you if you can't get the whole benefit out of it," said Tsitsipas.

"I know tennis is a sport where you get to make the decisions and you can decide for yourself, but sometimes an eye from the outside it can always help and maybe change certain outcomes of matches."