Jannik Sinner tested positive for the banned performance-enhancing steroid clostebol on two occasions in the spring.
The world number one has been cleared of punishment as the International Tennis Federation accepted Sinner's explanation that he had ingested the substance by mistake.
However, the investigation that followed and the uproar after the news has affected him, he says in his first statement after the doping revelation.
It has been very tough for me and my team. It still is, says Sinner according to AP.
The 23-year-old is preparing to enter the US Open on Tuesday. He will do so as the top seed and will face American Mackenzie McDonald in the first round.
It's not ideal before a Grand Slam tournament, but I haven't done anything wrong. It's a relief that I was cleared. The people around me know what kind of person I am, says Sinner according to AFP.
