The legendary coach and Sinner are lockstep in their belief in process and constant evolution.
Grigor Dimitrov has faced the Big 3 at their best and names the one Big 3 champion who was toughest to beat at his peak.
Miami Open champion has one primary aim for clay-court season.
The Bulgarian doesn't want to burden Sinner with comparisons, but adds that at the moment, no one is better.
The American used wisdom, experience and a few good physios to power through the Miami draw.
"This is my last season, and these are some of my final events. I want to remember these moments," Danielle Collins said.
The pair have remained great friends over the years, says Dimitrov.
