Both Sinner (in Miami last month) and Berrettini (in Madrid last week) reached Masters finals recently. Lorenzo Sonego, another Italian, won the Sardegna Open last month.

Sinner (No 18) and Musetti (No 82) are the only 19-year-olds in the ATP's Top 100.

Volandri, who leads the Italian Tennis Federation's high-performance center in Tirrenia, near Pisa, also credits collaboration with players' personal coaches.

The first joint "projects" began at an early age with Berrettini, who has been coached by Vincenzo Santopadre since age 14, and with Sonego, who has been with Gipo Arbino since 11.

Work with Musetti's team began before he won the 2019 Australian Open boys' title.

"We're all advisors available to the players and their coaches and teams. That's the big change in mentality that the federation made,"Volandri said.

It's a big departure from just a generation ago, when Volandri himself was Italy's top player, reaching a career-high ranking of No 25 in 2007.

"If you had a private setup, then that's all you had. You could train at Tirrenia, but there was no collaboration," he said. "Now the coaches all collaborate with me and with each other. Everyone talks to each other. So everyone is improving. The players are improving, the coaches are improving and the entire movement is improving."