Jannik Sinner's coach, Darren Cahill, has a close relationship with the Italian, but that does not stop him from respecting Carlos Alcaraz and enjoying his tennis.
Cahill was one of the most significant reasons for Sinner's rise to No. 1 in the rankings. He joined the 23-year-old's team in July 2022, and the improvements since then have been very impressive.
After making some progress in 2023, Sinner has broken through incredibly this year, winning the Australian Open and US Open and overtaking Novak Djokovic at No. 1 in June.
However, Cahill's importance extended beyond his coaching abilities after Sinner twice tested positive for the banned substance clostebol at the Indian Wells Open in March. That story only became public in August.
Despite being cleared by the International Tennis Integrity Agency, the World Anti-Doping Agency decided to appeal the case and is seeking a ban of between one and two years. A verdict is expected in early 2025.
That means Sinner will compete at the ATP Finals with that stress still hanging over him. He has kept his focus on the court impressively since the story first broke, but it must be challenging to do continually do that.
Sinner has spoken about Cahill's importance since that high-profile story broke. He said the Australian traveled with him longer than initially planned this season to support the Italian.
Cahill also plays a significant role in helping Sinner plan his schedule. The successful coach recently revealed that the two-time Grand Slam champion would make some changes to his calendar next year.
Sinner's biggest rival is undoubtedly Alcaraz. The Spaniard is also the only player to consistently beat Sinner this season, overcoming him three consecutive times at the Indian Wells Open, French Open, and China Open.
That run of losses against Alcaraz ended at the Six Kings Slam last month, but Sinner's victory in that match does not count in their official head-to-head because it came in an exhibition event.
Although Sinner and Alcaraz share a rivalry, Cahill told Gazzetta dello Sport that he respects Alcaraz and enjoys watching the 21-year-old and Sinner's epic matches in the stands.
"I have a lot of respect for him. I will never say that Sinner is better than Alcaraz or vice versa. If they meet in the final in Turin, I will cheer for Jannik and enjoy the show."
Cahill may never reveal who he thinks is the better player, but one of the men at last month's Six Kings Slam did not hide which player he thought was slightly better when producing their best tennis.
After being thrashed by Sinner in the opening round of the exhibition event, Daniil Medvedev stated in an interview that he used to think Alcaraz's game at its peak was better but had changed his mind after the drubbing he took at the Six Kings Slam.
The debate about which man is better will undoubtedly continue since the two men have years ahead of them to develop one of the best rivalries in tennis history.