Jannik Sinner entered the French Open as one of the clear favorites, backed by a 29-match winning streak and five Masters titles already in the bag. The Italian carried that momentum into his second-round clash against Juan Manuel Cerundolo, where he comfortably took the opening two sets.

However, the scorching Paris heat soon took a toll on the World No. 1 as Cerundolo capitalized and came back to win 3-6, 2-6, 7-5, 6-1, 6-1. While many believe that health problems were the main reason behind Sinner’s collapse, Andre Agassi thinks otherwise.

The eight-time Grand Slam champion felt that Sinner wasn’t able to adapt to the hot conditions in Paris and also raised serious questions over his preparation for Roland Garros

“It didn’t change a lot. Maybe if you gave me great conditions, I could stretch it to four hours 10. But [for Sinner] to go from him playing five-and-a-half hours last year in the final, to having the heat tap him in one hour 45,” Agassi told TNT Sports.

Last year, when Sinner met Alcaraz in the Roland Garros final, the showdown lasted 5 hours and 29 minutes. This year, however, his second-round clash against Juan Manuel Cerúndolo went on for 3 hours and 36 minutes. The stark difference in match duration reportedly raised questions from Andre Agassi, who was left wondering about the World No. 1’s preparation.

“There’s a difference between being fit and being prepared, and I have to point to a flaw in that kind of preparation, because there’s something you can do about that. It’s not that that dude doesn’t work hard, it’s not that he isn’t fit – he was one game away [from winning] and then the whole draw would have opened up. We all thought we’d see him here, maybe not lose a set,”

Sinner, who had been in complete control, suddenly lost three consecutive games to the world No. 56 before calling for a medical timeout. During the break, he was heard saying he felt “dizzy” and like he “wanted to vomit.”

Leading 5-1 in the third set, Sinner was just a game away from winning the match. However, this is where he started looking distressed and showed signs of discomfort. He wouldn’t be able to win another game in the set while Cerundolo won the next six games in a row to keep the match going.

Sinner had his serve broken five times during the final two sets as Cerundolo completely dominated. The Argentine then racked up the biggest win of his career while Sinner recorded his first defeat since the quarterfinals of the Qatar Open.

Analyzing Sinner’s unexpected capitulation, Agassi pointed out that he wasn’t drinking enough water during the match and this led to him facing “hydration” issues.

Agassi was skeptical if Sinner had taken the right diet before playing under the bright sun against Cerundolo and also felt that a player of his caliber shouldn’t be getting dehydrated within two hours.

“You have to force it, and it’s better to have it in you and not need it, than need it and not have it. I’d question his intake and if he’s doing it properly. I know nothing about his preparation. I know that he can play for five-and-a-half hours. He’s proven it. I know he’s the best player on the planet right now, but I also know there’s no excuse for him to run into a wall at an hour 45,” he further said.

This wasn’t the first time that hot conditions had become a major problem for Sinner in his Grand Slam campaign. The issues had first surfaced at last year’s Australian Open and it appears that his team are yet to figure out the solution to the frequently arising problem.

Jannik Sinner can’t seem to handle the heat at Grand Slams

Sinner had faced similar issues during his clash against Holger Rune at the 2025 Australian Open. After winning the first set, the Italian appeared to be struggling because of the humid conditions in Melbourne. This led to Rune mounting a comeback and winning the second set.

However, one of Sinner’s shots ended up breaking the net during the third set. This resulted in a short break, giving both the players an opportunity to head back into the locker room and refresh themselves. A defiant Sinner came back to the court and clinched the next two sets to win 6-3, 3-6, 6-3, 6-2.

Notably, Sinner once again had severe difficulty in playing under the sun at the 2026 Australian Open. The heat led to the 24-year-old suffering from cramps and losing control of his third-round clash against Eliot Spizzirri as the latter clinched the first set at the Rod Laver Arena.

Fortunately for him, the Grand Slam had a policy of closing the roof in extreme temperatures and this allowed him to get back into the match. Sinner eventually triumphed 4-6, 6-3, 6-4, 6-4. While he managed to come out victorious in the previous two instances, he wasn’t able to do the same against Cerundolo at Roland Garros this year.

After finishing the clay swing on a disappointing note, Sinner will be aiming to bounce back in the upcoming grass-court season. It remains to be seen if the Italian will be able to defend his title at Wimbledon that is set to commence from June 29.