Roger Federer reacts to Jannik Sinner's participation in the US Open after positive test for banned substances

Retired tennis star Roger Federer has spoken out about the controversy surrounding Jannik Sinner as the world's top-ranked tennis player battles for the US Open title after testing positive for a banned substance twice earlier this year.

“That's not something we want to see in our sport, that kind of news, whether he did something or not, or any other player,” Federer told Savannah Guthrie on TODAY on Sept. 3. “That's just noise that we don't want.”

Sinner was not suspended after testing positive for the anabolic steroid clostebol twice in March. An investigation by the International Tennis Integrity Agency found that the 23-year-old Italian star had ingested the substance accidentally.

“I understand it's a delicate situation,” said Federer, who won 20 Grand Slam titles in his career. “These allegations and problems are the nightmare of every athlete and every team because we have to fill out these forms all day, every day.”

“And it lives with you. Every morning when you wake up, you think, 'Is someone coming to the door to test me?' So it's really difficult.”

The decision not to ban Sinner sparked criticism from tennis fans, who said he received preferential treatment considering that other players in the past had been banned until their innocence of taking banned substances was proven.

After testing positive, Sinner won the Miami Open in March and then the Cincinnati Open in August.

“I understand the frustration you feel when you ask yourself, 'Was he treated the same as others?'” Federer said. “And I think that's what it comes down to.”

According to a press release, the ITIA ruled on Aug. 20 that Sinner was “not at fault or negligent” for his positive test. After each positive test, Sinner successfully appealed a provisional suspension, allowing him to continue playing, ITIA officials said.

Sinner told ITIA that the clostebol in his body came from contamination by a member of his care team who performed massage and sports therapy.

The tennis player said the support team member had a small wound and treated it with an over-the-counter spray containing clostebol. The team member then unknowingly infected Sinner through his skin during the massages and therapy.

According to ITIA, scientific experts concluded that Sinner’s explanation was “credible.”

“I think we all have a pretty good level of confidence that Jannik didn't do anything, but the inconsistency that he might not have had to sit out while they weren't 100 percent sure what was going on, I think that's the question that needs to be answered here,” Federer said. “But look, it is what it is and we also have to trust the process and everyone involved.”

Sinner is the No. 1 seed and has reached the quarterfinals of the US Open, where he will play fifth-seeded Daniil Medvedev on Sept. 4. Sinner defeated Medvedev in January to win the Australian Open, his first Grand Slam title.