Sinner re-hires former fitness coach Ferrera

World number one Jannik Sinner has re-appointed fitness coach Umberto Ferrara, with whom he parted ways following the investigation into his positive tests for a banned substance.

Ferrara and physiotherapist Giacomo Naldi left the Italian's team in August 2024, five months after he returned two positive tests for clostebol.

"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 read.

"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."

Wimbledon champion Sinner was initially cleared by an independent tribunal of any wrongdoing last August but the World Anti-Doping Agency (Wada) appealed against the panel's ruling that he "bore no fault or negligence".

Sinner ultimately accepted a three-month ban in February after reaching a settlement with Wada.

Wada said it accepted the four-time Grand Slam champion did not intend to cheat, but he bore responsibility for "the entourage's negligence".

Sinner said the substance clostebol, which can increase muscle mass, entered his system when Naldi applied an over-the-counter spray to treat a cut on his hand.

Ferrara says he provided the spray to Naldi for personal use and warned him not to use it on Sinner.

After the departures of Ferrara and Naldi, Sinner appointed fitness coach Marco Panichi and physiotherapist Ulises Badio in September 2004.

However, he parted ways with the pair shortly before this year's Wimbledon.

Sinner made his return to tennis at the Italian Open in May.

He lost the French Open final to Carlos Alcaraz in a five-set thriller in June, before beating the Spaniard in the Wimbledon final earlier this month to win his fourth Grand Slam.