Nine years ago, Juan Carlos Ferrero heard whispers about a special talent emerging near his academy in southeast Spain. Curious to see what the buzz was about, the former Spanish pro went to watch a 15-year-old Carlos Alcaraz compete in a tournament. Little did he know that first glimpse would mark the beginning of a partnership that started in 2018 and lasted seven years, before the two decided to go their separate ways.

While the 23-year-old Alcaraz quickly found a new head coach, Ferrero was left wondering what would come next. Now, though, it seems the Spanish coach may have found his next project, and it might involve a familiar Italian foe currently ruling the ATP rankings.

According to reports by Spanish journalist Gonzalo Ferreyra, Ferrero can join forces with Jannik Sinner‘s camp in the next season. Ferreyra stated that it was former ATP pro Jose Luis Clerc who had alerted him to the high-profile switch during the Cincinnati Open, and if the reports are true, it could be one of the biggest coaching defections in ATP history in recent times.

Notably, Simone Vagnozzi and Darren Cahill have been key members of Sinner’s team since 2022. Under the dual guidance of Vagnozzi and Cahill, the Italian finally realized his raw potential, marking a breakthrough moment in 2023 by winning his first Masters title at the National Bank Open. Since then, the Italian has clinched five Grand Slam titles and ten Masters 1000 titles, while also ruling the ATP rankings as the World No. 1.

However, Cahill had originally planned to leave Sinner’s team at the end of the 2025 season, but remained part of the Italian’s camp into 2026. In an interview with Digisport earlier this year, Sinner explained that plans had changed, confirming the Australian would stay for “one more year.”

The Italian also reflected on the importance of having Cahiil in his team and added, “Darren is a very, very important part of our team. He keeps all the team very close, and with his experience, it’s important, especially in moments where things don’t go our way. He’s important. We had a nice talk in the end of the year, last year, after the ATP Finals, and I tried to talk a bit in general.”

Sharing details on the Australian coach’s decision to stay for one more season, Sinner added, “He made a move what went in my favour and it was an important move, that he can stay for one more year, which for me, it is very important in this moment and the stage where I am. So him, with the combination with Simone, it’s a great combination. They know each other very well, they trust each other very well. So I think it has been very good.”

With the 2026 season nearing its end and Ferrero preparing to return to the Tour, the possibility of the Spanish coach joining Sinner’s team makes sense, particularly if Cahill is indeed set to leave after this season.

However, back in April, when the 2003 French Open champion was linked with Sinner, Ferrero initially dismissed the speculation before adding, “Just rumours. I haven’t had any contact with Jannik. I’ve been in contact with other players but not with him.” But just two months later, in June, Ferrero appeared more open to the idea, admitting that the prospect of working with the Italian was appealing to him.

He confessed, “Just a few months ago, I would have said no: the breakup with Carlos was recent, and I was not ready. But now that I feel stronger, I say: why not? Jannik loves to work hard and is willing to do whatever it takes to stay world no. 1. I like his attitude, and it would be wonderful to coach him.”

Nevertheless, there have been notable coaching switches on the ATP before, but none were between players at the peak of their powers and battling for all the biggest prizes in the sport. And if Ferrero indeed moves to Team Sinner, it will make for an intense showdown the next time Sinner and Alcaraz face off against each other, given the bond that Ferrero used to share with Alcaraz.

From Spotting Alcaraz at 15 to Their Shock Split

As a former Grand Slam champion and World No.1, Ferrero spotted Alcaraz’s potential when he was just 15 and chose to invest in his development at his own academy, passing up more lucrative coaching opportunities along the way.

Alcaraz has also consistently credited Ferrero for a significant part of his success. During their coaching partnership, the Spaniard won six Grand Slam titles and finished two seasons as the year-end World No. 1. That made their decision to split all the more surprising, especially after Alcaraz enjoyed one of the most successful seasons of his career in 2025 with Ferrero in his corner.

But a breakdown of contractual negotiations meant that their partnership reached its natural conclusion.

Speaking about their fallout, Ferrero made an emotional revelation in an interview with El Pais earlier this year, and stated, “When there’s a breakup like that, you feel sad at first, and then you’re left with a feeling of sadness for such a beautiful relationship that’s over.”

However, following their split, there was widespread speculation that Alcaraz’s on-court results would take a hit after Ferrero’s departure, but the Spaniard proved them all wrong. With Samuel Lopez at the helm of his coaching team, Alcaraz made the strongest possible statement, winning the Australian Open. During this time, the Murcian decided to increase family involvement in his career, bringing his older brother, Alvaro, onto his team.