After an almost flawless 2026 season, Jannik Sinner suffered a stunning collapse at the French Open. Leading by two sets and a break in the third, few expected the Italian to lose to Juan Manuel Cerundolo. Although he rediscovered his form and battled the heat at the All-England Club to defend his title, his coach now believes those collapses are something he must learn to live with in the future.

“I don’t think there’s a single cause; many small things, when combined, can lead to these small slumps, but let’s remember that there have been four in the last five years,” Simone Vagnozzi, Sinner’s coach, said in an interview with Corriere della Sera. “These guys aren’t robots. Heat, fatigue, and tension can all combine. The temperature in Paris was prohibitive, and he arrived there under significant physical and mental stress. In short, there’s no single factor; in that case, it would be easier for us to correct it.”

“We have to live with these episodes, working to avoid them. There can be a strong, stupid player. But there can never be a stupid champion,” the 43-year-old added.

His comments came after the world No. 1 had dealt with several similar issues in recent years before Paris. One major example came during the Shanghai Masters last year when his title defense ended disappointingly.

The 24-year-old was forced to retire against Dutch ace Tallon Griekspoor. The contest was played in brutally humid conditions in Shanghai, and it made the challenge even tougher.

During the deciding set of his third-round match, Sinner appeared to be struggling with a cramp in his right thigh. Later, the five-time Grand Slam winner was unable to continue and had to retire.

Another setback came at the Cincinnati Open. After falling behind 0-5 in the opening set of the final, Sinner suddenly retired against Carlos Alcaraz.

Combined with the intense heat in the final and his physical issues in the semis against Terence Atmane, it became too much to handle.

Now that the Italian coach has admitted these episodes are something Sinner has to deal with, the focus shifts to what comes next.

Rennae Stubbs supports Jannik Sinner’s Canadian Open withdrawal

After the French Open heartbreak and SW19 triumph, many expected the Italian to return at the Canadian Open in August. Instead, his plans changed.

The Italian officially withdrew from the Canadian Masters, ruling him out of the tournament before it even began.

However, Rennae Stubbs, the current coach of Serena Williams, has since backed Sinner’s decision. The Aussie believes the withdrawal was the right call, as the Italian may have learned from an earlier mistake.

“I don’t blame Jannik for not playing,” Stubbs added on ‘The Rennae Stubbs Tennis Podcast’. 

“It was a bear of a schedule for him, doing what he did. He played all those clay court tournaments, lost that really tough match at the French, then goes and wins Wimbledon. He did not play anything prior. Maybe he learnt a lesson about the load of tennis which he did before the French,” she added.

It was a golden opportunity for Jannik Sinner after becoming the only man to win the first 5 Masters events of a calendar year. The feat also gave the current top seed a chance to achieve something no player had ever done before: winning all nine Masters 1000 titles in a single season.

However, that historic bid came to an end after his withdrawal.

Following his withdrawal from Canada, the 24-year-old’s next scheduled tournament is the Cincinnati Open. With renewed energy after taking time to rest following SW19 heroics, Sinner will head into Cincinnati with fresh motivation.