"The worst career decision Jannik Sinner has ever made" - Fans blame Italian's controversial fitness coach after his concerning MTO in US Open SF

Jannik Sinner overcame abdominal discomfort to win his semifinal clash against Felix Auger-Aliassime at the 2025 US Open. Despite Sinner's four-set win, which helped him set up a final meeting with Carlos Alcaraz, many of the Italian's fans accused his fitness coach Umberto Ferrara of not doing his job well.

Ferrara was sacked by the World No. 1 last year after it was disclosed that the fitness coach was responsible for giving the topical medication containing Clostebol to Sinner's physio, Giacomo Naldi. The Italian twice tested positive for the banned substance last year, which resulted in a three-month ban for him following his Australian Open title triumph in early 2025.

Controversially though, Ferrara was reappointed by Jannik Sinner after his title-winning run at this year's Wimbledon Championships. Since restarting his collaboration with the fitness coach, the World No. 1 has experienced a number of on-court issues. For instance, in the final of the Cincinnati Open against Carlos Alcaraz, the Italian retired mid-match citing illness.

During his US Open semifinal outing against Auger-Aliassime, Sinner needed to take an off-court medical timeout (MTO) with his abdominal discomfort adversely affecting his serve. Several loyal fans of the Italian took to X (formerly Twitter) and laid the blame for the four-time Major champion's persistent physical issues at Ferrara's feet.

"Genuinely the worst career decision he has ever made," one fan wrote.

"Excuse me but Jannik had a stellar few months and the moment Ferrara rejoins the team it’s the arm, the blisters, the flu, the food poisoning. f**k that guy," commented another.

"Ever since Ferrara came back Sinner has been absolutely rancid, he’s sucking the life out of him like Nosferatu with lily rose. please Jannik," another fan chimed in.

There were others who questioned Sinner's shocking decision to sack fitness coach Marco Panichi and physio Ulises Badio in the buildup to his Wimbledon campaign this year. The Italian had originally hired Panichi and Badio in 2024 after Ferrara and Naldi were removed from his camp.

"You know what the fact that he fired panichi and badio p**ses me off more than hiring back Ferrara. They were good for him idk why the hell he thought it was a good idea to dump them and bring back "Ferrara"," one stated.

"He was able to go toe to toe with Carlos at the French without an MTO or bathroom break when he was with Uli and Panichi :( Wish he could bring them back," added another.

"I still can’t believe he fired them like that. Absolutely worst decision in his career," weighed in yet another fan.

"It's nothing serious" - Jannik Sinner downplays abdominal problem after securing progress to US Open final

Jannik Sinner at the 2025 US Open (Source: Getty)

Upon returning to the Arthur Ashe Stadium court from his off-court MTO, Jannik Sinner began serving somewhat normally again. After clinching the 6-1, 3-6, 6-3, 6-4 win over Felix Auger-Aliassime, the Italian briefly touched on the abdominal discomfort that led to him taking the MTO. According to the World No. 1, the issue isn't a serious one.

"It’s nothing too bad. I served after always a little bit faster again, so no, it's nothing serious," Sinner said in his post-match, on-court interview.

Only time will tell if the discomfort rears its ugly head in Jannik Sinner's clash against Carlos Alcaraz in the men's singles final of the 2025 US Open. Alcaraz has been in red-hot form at Flushing Meadows, having reached the final without dropping a set. The Spaniard also leads the pair's head-to-head 9-5.