ATP under-25 No. 3: Jannik Sinner
I almost – almost – had Jannik Sinner number 4 here. But I think that long-term the 21-year-old Italian will finally hone his game enough where he is consistently battling for tournament titles. He went on a bit of a run at the end of 2021 when he won three tournaments and only lost to players who are really good (like Daniil Medvedev, Frances Tiafoe, and Carlos Alcararz).
But then Sinner only won one tournament in 2022 (albeit against Alcaraz at the Umag Open where he destroyed Alcaraz in the last two sets 6-1 6-1). Still, he was mostly losing to players like Alcaraz and Stefanos Tsitsipas so Sinner was better than his competition against lesser players. Truly great players need to rise above all of their competition, though.
Sinner has proven he can defeat nearly anyone on the ATP tour. Against Alcaraz at tour-level tournaments, Sinner is 3-3. Against Ruud, Sinner is 2-0. Sinner needs to learn to be better on grass, but he is just fine on hard court (7 of his 8 tour titles have come on that surface) and Sinner has won one tour title on clay (the Umag Open against Alcaraz).
Is Sinner going to win Wimbledon? That is unlikely though he moves well and has the game to win on that surface. But Sinner could be a real threat at the US Open. If Sinner can learn to be more consistent, he is a threat at any major in 2024.