MILAN -- "Can you say something useful and not be this useless all the time? Just say one thing that is actually useful."
"Go more to the net ... not just to shake hands."
And with that, stand-in coach Marcelo Melo let Alexander Zverev return to the baseline with, hopefully, a winning tactic.
Player coaching, normally forbidden during a men's match, is being trialed at the ATP's Next Gen Finals in Milan this week, and conversations like the above are giving fans new insight, and entertainment.
Coaches and players conversing through headsets at the end of sets is one of the new rules being applied, along with shorter sets, no-Ad scoring, medical timeout limits, and no lets on serve.
But, for the players, the most popular innovations are the shot clock, and Hawk-Eye making all the line calls.
The on-court clocks enforce the 25-second rule between points, and shorter warm-ups ensure matches begin precisely five minutes from the second player walk-on.
Zverev withdrew from the Next Gen Finals to focus on the ATP Finals starting on Sunday in London, but turned up in Milan on Tuesday to play an exhibition match against alternate Stefanos Tsitsipas, and with Melo acting temporarily as coach.
"The Hawk-Eye calling all the lines, that would be something that I wouldn't mind at all," Zverev said. "The shot clock is something not bad. There has to be a few adjustments maybe made to that but I think that has potential."
ATP executive chairman and president Chris Kermode believes the clocks will become a feature on the regular tour from 2019.
"Next year, for sure not, but I think 2019 there's a possibility," he told The Associated Press.
"To me, having a shot clock, people have been talking about it for years and it's like can we just do it or not do it? This is clearly let's just do it. The reduced warm-up for sure we can get done, too, and the rest is then up for discussion.
"You've got to have a year's lead-in so everyone is fully aware of what's happening. You can't just thrust it upon them and go, 'By the way, January, guys, you're playing under different rules.' Also I think we need to analyze the success of this week. This is just day one. Let's take all the data through all the matches, see what works, what doesn't work."
The most drastic change is the shorter set, where the first to four games takes the set, with a tiebreak at 3-3.
While Kermode says it is his favorite innovation, he recognizes it is unlikely to be brought in anytime soon.
"There are a couple of no-brainer ideas that we should be doing," he said. "But once you start the dramatic scoring format changes that's going to be the most difficult. I'm actually a big fan of the system but I'm aware of the challenges.
"Will this happen on the tour in the next five years? Probably not. But 10 years down the line could this be the way it's played? Yeah, it could be."
Automatic line calling was another change that was met with universal appreciation.
Hawk-Eye cameras decide all line calls, eliminating the need for line judges and ensuring the chair umpire is the only match official on court.
When triggered, the new system will make an instant automated "out" call.
"For now, live Hawk-Eye is a good thing," No. 2 seed Karen Khachanov said after losing to Daniil Medvedev. "Only thing is I would like to hear different voice."
Khachanov said he'd prefer if the Hawk-Eye recorded the voice of whoever was the chair umpire, so the calls sounded more legitimate.
Kermode said the ATP will consider feedback from the players, as well as different generations of fans, the sponsors, and the media.
"I don't want to run the tour dictatorially," he said. "We need to take everyone's feedback, and analyze it properly and strategically. If we do this over the next two or three years and we decide the game is absolutely perfect that is fine, too, but at least we've taken a good look."