Rick Macci, who played a major role in developing Serena Williams‘ early career, has jumped into one of the most talked-about coaching rumors with a statement that directly contradicts what everyone else is saying.

Reacting to reports linking Juan Carlos Ferrero to Jannik Sinner’s camp for 2027, Macci argued the move would actually backfire on Sinner rather than help him solve his biggest rival. 

“If Ferrero end up coaching/helping Sinner my take is the exact opposite,” Macci wrote on X. “This would help Carlos the most if they played. Now he mentally digs even deeper (if possible) and beats both of them now and then. Adversity makes greatness stronger. Greatness finds another gear ear to ear.”

“Plus the pro travel coaches get way too much credit and way too much blame. Anybody can help anybody and a different set of eyes is sometimes good as long as they are not crossed. When Carlos is in FULL FLIGHT no matter what the opponent knows or does it is still GOODNIGHT.”

The general interpretation of the rumor has been quite the opposite. Since Ferrero spent seven years inside Alcaraz’s team, most assumed his inside knowledge of Alcaraz’s habits and weaknesses would give Sinner a direct edge in their rivalry, essentially handing the Italian a scouting report no other coach could match. Macci’s rebuttal dismisses that logic entirely, suggesting coaching doesn’t make much difference in either direction and that, if anything, Alcaraz will further upstage his game with a new source of motivation in front of him. 

After the separation in December 2025, Ferrero spent most of 2026 away from the tour. He briefly worked with a young golfer and spent time with his family before confirming on September 15 that he is planning to return to coaching in 2027. He kept the identity of his next player hidden, stating he could not reveal it yet. 

That silence opened the door to the current wave of speculation. Argentine journalist Gonzalo Ferreyra reported that former player and ESPN Latin America commentator Jose Luis Clerc had hinted that Ferrero would join Sinner’s team next season, claiming Sinner had learned of the possibility during this year’s Cincinnati Masters. 

Naturally, the timing dovetails with another narrative: Sinner’s current coach Darren Cahill is likely to leave at the end of this season, having forfeited a bet that was tied to Sinner’s Wimbledon draw this year, and no wager exists to ensure his return for 2027. In the scenario being floated, Ferrero would join in tandem with Simone Vagnozzi, rather than being his replacement outright.

Other names have also been floated as candidates for Ferrero’s next post, including rising Spaniard Rafael Jodar, Felix Auger-Aliassime, and Holger Rune, with some reports noting that the logistics of Ferrero’s academy being based in Spain make a partnership with a Spanish player like Jodar more practically convenient than uprooting Sinner’s training base. Nothing has been confirmed by Ferrero or Sinner’s team, but the 2003 French Open champion has previously acknowledged only that he would enjoy working with the Italian, stopping well short of confirming any agreement.

Alcaraz-Ferrero separation

The speculation traces back to one of the more dramatic coaching splits tennis has seen in recent memory. In December 2025, Alcaraz informed Ferrero of his decision to break their partnership after seven years, which led to six Grand Slam titles and helped Alcaraz become the youngest world No. 1 in tennis history. 

The split came as a genuine shock given it followed a strong season, and Alcaraz posted an emotional message thanking Ferrero for helping make his “childhood dreams a reality.” Samuel Lopez, who was already a part of the setup, took the lead in 2026 and guided the Spaniard to his first Australian Open title and completing a career Grand Slam.