Alcaraz has been training with Matteo Berrettini ahead of another season, with the Italian having won the Davis Cup alongside Sinner.
Meanwhile, Joao Fonseca has emulated Alcaraz and Sinner, with the 18-year-old becoming the third teenager after the duo to win the Next Gen ATP Finals.
But he has a long way to go to catch Sinner in particular in terms of titles, with the Italian having won eight times in 2024.
He took his career tally to 18 this season, where he won the Australian Open and US Open for his first Grand Slam titles.
Mats Wilander makes ‘very bold’ Jannik Sinner and Carlos Alcaraz prediction
Alcaraz meanwhile is not far behind on 16 titles, with his four wins in 2024 including the French Open and Wimbledon.
And both have now been involved in a big claim by Mats Wilander, who was asked by Eurosport for his bold prediction of 2025.
“My very, very, very bold prediction for 2025 is that Carlos Alcaraz or Jannik Sinner will win the calendar Grand Slam,” he said.
