Darren Cahill is helping Jannik Sinner play razor-sharp tennis

After his 6-2, 6-4 win over Andrey Rublev on Tuesday in Miami, Jannik Sinner was asked an odd, but highly appropriate, question by his on-court interviewer:

“Did you execute your game plan to perfection?”

Sinner’s answer was just as appropriate, and believable:

“For sure,” the Italian said.

What other answer could he give? There was no room for false modesty after a performance like this one.

Sinner was razor sharp from first point to last. He broke in the third game with a nice forehand drop shot, and an even nicer dipping forehand pass two points later. He broke again with a running backhand pass that would have made Novak Djokovic proud, and followed it with a crosscourt return winner that would have made the Serb even prouder. He held for 5-1 with a beautifully controlled shot-top volley, and a blistering overhead smash from the back of the court.

Even when he came down from the trees a bit in the second set, Sinner stayed composed and opportunistic. He got the one break he needed with a reflex backhand return, and then, at 5-4, he survived a tricky closing service game. With the score at 30-all, Rublev forced Sinner into a lengthy rally. Sinner was tighter than he had been earlier; the important thing was that he knew it, and he adjusted for it. Instead of aiming for a corner or trying for an early winner, he played with a little more margin, and was finally rewarded with a Rublev misfire.

In all, Sinner hit 29 winners and made just two errors; won 86 percent of his first-serve points; and beat the No. 7 player in the world in 72 minutes.

Darren, we speak not so much before the match, but he gives you a little bit of mental advice, no? The most important, he always says, be proud where you are and have fun when you play. Jannik Sinner

Sinner has said he has one goal for 2023: “Trying to improve every day.”

That methodical approach has led, so far, to the desired results. After a season in which he surprisingly failed to make the ATP Finals in Turin, Sinner has returned to the steady progress that characterized his first two years on tour. He has won a title, in Montpellier; made a 500-level final, in Rotterdam; and a 1000-level semifinal, in Indian Wells. At the Australian Open, he lost in five sets to eventual runner-up Stefanos Tsitsipas. Over the last two weeks, he has wins over two Top 10 opponents in Rublev and Taylor Fritz.

Sinner, unbelievably, is still just 21, but it feels as if he has already had three stages to his career. The first was his meteoric rise into the Top 20 as a teenager; from the start, he hit the ball as cleanly and powerfully as anyone in the game, and many of us thought we were looking at a future No. 1. Then came a bit of stagnation, some inconsistent results, and some close losses—most famously to Carlos Alcaraz at the US Open last year. Was Sinner happy just to be in the Top 10? Was his 6-foot-5 height too much of a liability on defense? Was he destined to be a close-but-not-quite kind of guy?

With Cahill in his corner, though, a third stage seems to have begun. Here was someone who has coached No. 1 players on the men’s side (Lleyton Hewitt, Andre Agassi) and the women’s side (Simona Halep). Here was someone who would expect the most—as in, Grand Slam titles—from Sinner. Here was someone who Sinner would want to please and play his best for. Together they’ve worked on making his ultra-lean body stronger, and getting him to tailor his tactics to specific opponents, rather than just swinging away.

“We’ve started to learn the opponent much better, which is one point where, for sure, all of us invested a lot,” Sinner says of his coaching team. “Where in the beginning was tough for me to understand, because I used to play with only my game plan, but not with my opponent’s one.

“At some point [last year], I was a little but struggling on court to understand when to do this or not. Now I’m a different player. All this kind of stuff is part of my growing.”

According to Sinner, Cahill’s most important contribution is a simpler one: He makes sure the Italian keeps his head up, and enjoys the ride.

“Darren, we speak not so much before the match, but he gives you a little bit of mental advice, no?” Sinner says. “The most important, he always says, be proud where you are and have fun when you play.

“Even if I don’t smile a lot, but still, I have a lot of fun,” the self-contained Sinner insists.

Most players would be having fun if they were in the Miami quarterfinals having not dropped a set. Sinner will play Emil Ruusuvuori or Botic van de Zandschulp next, and looming in the semifinals is the possibility of another shot at Alcaraz.

So far the Spaniard has out run the Italian in the race for No. 1, but at 19 and 21 years old, their rivalry will likely be a marathon rather than a sprint. Sinner has already learned a lot in his time as a pro. He looks poised to show it off, and maybe win one an epic match for himself, as the stakes get higher in the coming months. He has a game plan, and he’s executing it as well as he can.