Jannik Sinner Reunites with Former Trainer

Photo credit: Antoine Couvercelle/ROLEX

By Richard Pagliaro | Wednesday, July 23, 2025

Jannik Sinner has reunited with his former trainer he previously fired.

World No. 1 Sinner announced he has rehired Umberto Ferrara as he trains for the upcoming North American summer hard court swing.

Sinner, who withdrew from Toronto over the weekend, plans to make his competitive return in Cincinnati next month. It will be Sinner’s first tournament since he dethroned two-time defending champion Carlos Alcaraz in the Wimbledon final to make history as the first Italian to win The Championships.

“Umberto has played an important role in Jannik’s development to date, and his return reflects a renewed focus on continuity and performance at the highest level,” a statement from Sinner’s team said. “The decision has been made in alignment with Jannik’s management team as part of ongoing preparations for upcoming tournaments, including the Cincinnati Open and US Open.” In March of 2024, Sinner twice tested positive for the banned steroid clostebol in “low levels” the International Tennis Integrity Agency announced in August days before the start of the 2024 US Open. 

Sinner was not suspended and permitted to play because an independent tribunal ruled he was at “no fault” for the steroid contamination in his system. 

Shortly before the Open, Sinner parted with Ferrara and Giacomo Naldi. Days before the start of the 2024 US Open, Darren Cahill, one of Sinner’s coaches, attributed his positive test to contamination. 

“Everybody has to know that Jannik had no part in this at all,” Cahill told ESPN. “He didn’t elect to ingest anything. He didn’t take any tablets. He didn’t intend to cheat. 

“Somehow he’s tested positive through this connection to this particular spray from [physiotherapist] Giacomo through to Jannik. We don’t know how. Working on the feet, a massage, whatever it may be. And he’s given two positive results from that.” 

Coach Cahill said Sinner and his team first learned he tested positive for the banned steroid Clostebol shortly after he won the Miami Open championship in March, 2024. Cahill traced the positive test to Sinner’s physiotherapist, Giacomo Naldi, who the team claims inadvertently contaminated Sinner with a medication he used to treat a cut on his finger. 

The medication, available over the county in Italy and other European countries, was given to Naldi by Sinner’s trainer, Umberto Ferrara, Cahill said in recounting the chain of events that led up to the two failed doping tests.

Sinner successfully appealed both provisional suspensions claiming inadvertent contamination and was permitted to play while his case was under investigation. 

“Straightaway they worked it back to knowing that it must have come from this particular spray that the physical trainer had on him,” Cahill said. “So what happens from there is you go to sports resolution because they give a suspension straight away so to get that suspension lifted Jannik’s team had to go to sports resolution and have an emergency meeting. 

“The story was told exactly how it happened. That Jannik played no part in it. That he’s incredibly professional, that he supports anti-doping, that he does everything around his team to make sure something like this would not happen. And they accepted how it happened, saw it was no fault from him.”

“So they allowed him to continue to play and then the ITIA would do their due diligence and make sure it was all credible.”  

That decision prompted WADA to appeal the case—and seek a one to two year ban. Earlier this year, Sinner accepted a three-month suspension to settle the WADA Appeal. 

“This case had been hanging over me now for nearly a year and the process still had a long time to run with a decision maybe only at the end of the year,” Sinner said in a statement in February accepting the suspension. “I have always accepted that I am responsible for my team and realize WADA’s strict rules are an important protection for the sport I love. 

“On that basis I have accepted WADA’s offer to resolve these proceedings on the basis of a three-month sanction.”