NEW YORK (AP) — Jannik Sinner fired his fitness trainer and physiotherapist because of his two positive steroid tests in March and said Friday at his pre-U.S. Open news conference — his first public comments on the matter — that he knew he was innocent but worried what the case’s outcome would be until finding out he wouldn’t be suspended.

Sinner’s fitness trainer, Umberto Ferrara, and his physiotherapist, Giacomo Naldi, have been at the 23-year-old Italian’s side during his rise over the past two years, which included his first Grand Slam title at the Australian Open in January and ascension to the No. 1 ranking in June . “I’m not feeling that confident to continue with them,” Sinner said.

“Now I just need some clean air.” The International Tennis Integrity Agency (ITIA) announced this week that Sinner failed two drug tests — one during a tournament in Indian Wells, California, and one eight days later — but that it was determined the banned anabolic steroid Clostebol entered his system unintentionally through a massage from Naldi. “Obviously it has been a very tough moment for me and my team,” Sinner said.

“It still is, because it’s quite fresh.” Play begins Monday at Flushing Meadows . Sinner is the top-seeded man and is scheduled to meet first-round opponent Mackie McDonald , an American ranked 140th, on Tuesday.

“Of course it’s not ideal before a Grand Slam,” Sinner said with a chuckle about the timing of the news. “But in my.