Jannik Sinner and Carlos Alcaraz will be back in action at the ATP Finals this year. The Italian is the defending champion at the event and will enter after a successful run in the Paris Masters.Alcaraz and Sinner have been the top two players this year. While the Spaniard claimed the honors in Paris and New York, Sinner defended his title in Melbourne and captured his maiden crown at Wimbledon.Both players have arrived in Turin for the ATP Finals. While fans were expecting some intense rivalry at the season’s final event, the two surprised everyone by sharing a cheerful selfie after a friendly practice set on court.Here’s how fans reacted on X after getting a glimpse of their latest selfie."Miss those days when rivals hated each other," One user saidAnother fan urged them to keep the camaraderie only off the court:"Cute selfie!! (pls don't be cute with the tennis we need to win)."This user wished to witness a rivalry like that of Serena Williams and Maria Sharapova."I desperately need og Serena-Maria rivalry."Another fan appreciated the respect they shared for each other."Beautiful message they are giving to everyone who follows this sport and especially to the children, great rivalry but always prioritizing mutual respect!!! Thank you for the year they have gifted us and for those that I'm sure will come."This user was surprised to witness the lack of intensity with the top spot in the ATP Rankings on the line."Is it a battle for the number one spot?"This fan felt that their friendship affected the intensity of their matches."They’re too chummy for me! I liked it when rivals didn’t like each other! It made their matches so intense."I think it's special, splitting Grand Slams, fighting for the great things" - Carlos Alcaraz on his rivalry with Jannik SinnerCarlos Alcaraz and Sinner at the Turin Nitto ATP Finals 2025 - Source: GettyCarlos Alcaraz has defeated Jannik Sinner four times this year. He trails the Italian by 250 points in the ATP Rankings.Alcaraz spoke about his rivalry with Sinner after defeating him in the US Open finals. The Spaniard also revealed his practice sessions are focused on beating Sinner on tour.“For me it’s great,” said Carlos Alcaraz, who explained how battling Sinner helps him improve. “I think we push each other to the limit every time. My practices are just focused to see how I can be better just to beat Jannik. So I think the rivalry, it is special, splitting Grand Slams, fighting for the great things.”The 22-year-old has captured eight titles this year, including two Majors. He will be eager to finish on a strong note and make his mark in Turin.Alcaraz will enter Turin after a second-round exit in Paris. Despite a resilient performance against Cameron Norrie, the Brit outfoxed him 4-6, 6-3, 6-4.