Sinner was outclassed by his rival on Arthur Ashe Stadium, producing a well-below-par serving performance in the final.<\/p>\n
![\"Carlos](\"https:\/\/www.newsbeep.com\/us\/wp-content\/uploads\/2025\/09\/GettyImages-2234195389-1024x683.jpg\")
Photo by Clive Brunskill\/Getty Images<\/p>\n
Many highlighted the shot as a weakness in his game after the match, with Italian tennis legend Paolo Bertolucci claiming Sinner must improve his serve<\/a> if he wants to beat Alcaraz in the future.<\/p>\n Since then, footage has been leaked of Sinner<\/a> in training, which suggests he may have listened to his countryman.<\/p>\n Ahead of his trip to China for the beginning of the Asian swing, Sinner has been training in Monte-Carlo.<\/p>\n The Italian was seen focusing on his serve in training, with one particular clip showing Sinner practising the shot without a racket in hand.<\/p>\n At the Monte-Carlo Country Club, Jannik Sinner is working on his serve \u2014 this time without a racquet. pic.twitter.com\/tkz059ho8r<\/a><\/p>\n \u2014 The Sinner Times (@sinnertimes) September 16, 2025<\/a> <\/p>\n View Tweet<\/p>\n Such emphasis on the serve can only be good news for fans of the world number two, who raised their concerns over the shot during the US Open.<\/p>\n Sinner\u2019s serve was far from its best at Flushing Meadows, but was particularly poor in the final, where he trailed Alcaraz in every meaningful statistic.<\/p>\n PlayerAcesDouble faults1st Serve %Win % on 1st ServeWin % on 2nd ServeCarlos Alcaraz10061%83%57%Jannik Sinner2448%69%52%Serving stats from Carlos Alcaraz vs Jannik Sinner<\/p>\n Making just two aces to Alcaraz\u2019s ten, Sinner struggled to take control of his service games, which led to him being broken on five occasions.<\/p>\n Working on his serve in training, Sinner has followed in the footsteps of his rival, who did the same thing earlier this year.<\/p>\n Carlos Alcaraz fixed his serve during the 2024\/2025 off-season<\/p>\n Ahead of the 2025 season, Alcaraz made a significant change to his serve<\/a>, looking to become more efficient.<\/p>\n Alcaraz admitted it was taking some time for the adjustments to feel natural before the Australian Open<\/a> began.<\/p>\n \u201cRight now, I am still thinking about it. I am still reminding myself how I have to do it,\u201d he said.<\/p>\n \u201cEvery day is getting better and better and feeling better and better with it. We knew I had to change something in the serve to be better at it.\u201d<\/p>\n The improvements weren\u2019t evident right away, as Alcaraz lost to Novak Djokovic<\/a> in the Australian Open quarterfinals, hitting five double faults in that match, but he was right up to speed by the time the US Open came around.<\/p>\n Producing arguably the most clinical serving performance of his tennis career, Alcaraz won his sixth Grand Slam title in style.<\/p>\n
A key element that let him down at the US Open, especially in the final.
Sharpening every detail as he prepares for the season\u2019s closing stretch. \ud83e\udd8a\ud83c\udfbe<\/p>\n![\"Jannik](\"https:\/\/www.newsbeep.com\/us\/wp-content\/uploads\/2025\/09\/GettyImages-2223621666-1024x683.jpg\")
Photo by HENRY NICHOLLS\/AFP via Getty Images<\/p>\n![\"Carlos](\"https:\/\/www.newsbeep.com\/us\/wp-content\/uploads\/2025\/09\/GettyImages-2193247877-1024x683.jpg\")
Photo by Andy Cheung\/Getty Images<\/p>\n