Jannik Sinner fires trainer, physio amid doping furore

The Italian tested positive for the steroid clostebol, which can be used to build muscle mass, after his physio Giacomo Naldi applied an over-the-counter spray to a cut on his own hand before carrying out treatments on Sinner. The spray was given to Naldi by trainer Umberto Ferrara.

The Australian Open champion was cleared of fault or negligence by a tribunal last week, accepting Sinner's explanation that he had inadvertently been contaminated with the substance by Naldi, the International Tennis Integrity Agency (ITIA) said.

The positive doping tests came to light on Tuesday, a day after the Italian won his fifth title of the year at the Cincinnati Open.

"They (Naldi and Ferrara) have been a huge part for my career," Sinner said in a news conference at the US Open on Friday.

"We made an incredible job, bringing a lot of success and then having a great team behind me.

"Now, because of these mistakes, I'm not feeling that confident to continue with them. I was struggling a lot in the last months. I was waiting for the result. The only thing I need right now is some clean air."

Sinner's case has created a storm considering other players who failed drugs tests usually get suspended during the course of the investigation.

Sinner has repeatedly maintained his innocence and said he was able to keep playing because his team quickly identified the source of the contamination.

"The reason why I could have played was because we knew where the substance was in and how it came into my body," he said. "This is very important, making this process, to letting them know, and they understood it straightaway."

REPUTATION DAMAGE

Asked if he had concerns about the damage the controversy might cause to his reputation, Sinner said: "In my mind, I knew that I haven't done anything wrong.

"Whoever knows me very well knows that I haven't done and I would never do something what goes against the rules.

"About the reputation, we will see moving forward, no? Because this, I can't really control."

Current and former players have alleged a double standard, questioning why Sinner was not immediately suspended like other players who had tested positive.

"Plenty of players go through the same thing and have to wait months or years for their innocence to be declared," British player Liam Broady wrote on social media.

ESPN analyst and 18-time major winner Chris Evert said she believes top-ranked players like Sinner face different consequences after a positive test.

"I do think that they protect top players," she told reporters this week. "I do think there's some protection there, than if you were Joe Smith, ranked 400 in the world."

Sinner insisted that he received the same treatment as his fellow players.

"Every player who gets tested positive has to go through the same process. There is no shortcut, there is no different treatment, they are all the same process," he said.

"I know sometimes the frustration of other players obviously. But maybe because they got suspended is they didn't know exactly where it comes from, also what substance, but the main reason is where it comes from and how it entered in his own system. We knew it straightaway."

American Frances Tiafoe, the last player to face Sinner before the news broke, sidestepped the controversy on Friday.

"Government bodies do what they did. Obviously, he's cleared to play and that's obviously all that matters. I'm just trying to focus on the U.S. Open," he told reporters.

The US Open starts on Monday.