Novak Djokovic backed Alexander Zverev after the German branded the ATP 'a disgrace' due to their scheduling at the Madrid Masters.
Djokovic, who beat Aslan Karatsev in his opening match at the Rome Masters on Tuesday, spoke out in defence of Zverev and urged the ATP to make changes to help players.
Zverev was unhappy at the scheduling of his matches in Madrid, with him required to finish late every day.
That was not too much an issue throughout the tournament when he could simply start the next day late again, but he was thrashed in an afternoon final by Carlos Alcaraz, which he put down to not being given enough time to recover.
While many have criticised Zverev claiming his is simply demonstrating sour grapes, Djokovic says he agrees with the world number three entirely.
"You cannot end your semi-final match at 1am and play the final the following day," Djokovic said.
"I understand that they want to sell more tickets by scheduling a night session on Saturday, but it may cause problems.
"The organisers should talk to players before making this kind of decisions.
"When I was the President of the Player's Council several years ago, I tried to solve this issue. But still, nothing changed."
Djokovic was in imperious form himself in Rome, beating former Australian Open semi-finalist Karatsev 6-3, 6-2.
On the match itself, Djokovic said: "When you see him, physically, [he is] a very strong guy,"
"You never know with him. If he's feeling the ball, he can be very dangerous because he stays so close to the line, puts pressure on his opponents.
"He was missing a lot of balls today though. He gave me a couple of breaks there in the first and second sets, but I'll take this win for sure.
"It's a straight-sets win against a quality opponent and I'm looking forward to the next challenge.
"You always hope you can play some exciting and attractive points, and that you can come out as the winner of those points and celebrate with the crowd, obviously.
"That's what the crowd is looking for. Energy, excitement, fight, and they want to see some good tennis.
"We had some nice points today. It's always good to play in the Colosseum of tennis, and this stadium certainly is."