World No.1 Jannik Sinner admits the ongoing doping saga surrounding him is playing on his mind as he prepares to defend his Australian Open crown.
The 23-year-old Italian has arrived in Melbourne - where he faces Chile's Nicolas Jarry in the first round - with lingering uncertainty over his playing future.
It comes after the Wold Anti-Doping Agency appealed a decision to clear Sinner after he twice tested positive for an anabolic steroid last March.
The International Tennis Integrity Agency had accepted Sinner's explanation that the banned substance entered his system unintentionally via a massage from his physiotherapist.
But Sinner could still serve a suspension of up to two years if he is found guilty by the Court of Arbitration for Sport, which is yet to set a date for the appeal hearing.
"We are in a stage where we don't know many, many things," Sinner said on Friday at his pre-tournament press conference.
"Yeah, you think about this, of course. I would lie if I would tell you I forget. No, it's not like this.
"It's something what I have with me now already for quite a long time, but it is what it is.
"I'm here trying to prepare for the grand slam. Let's see how it goes."
Sinner has come under fire from rivals, most notably Nick Kyrgios, who said positive tests from the Italian and then-women's world No.1 Iga Swiatek last year were a "disgusting" look for the sport.
Kyrgios hasn't let up, continuing his public crusade against Sinner in recent months.
The Australian firebrand took a more subtle swipe on Friday when he told reporters: "I'm very confident in myself that I'm not going to be accidentally putting something in my system."
A few hours later, Sinner refused to bite back.
"I haven't done anything wrong - that's why I'm still here, that's why I'm still playing," he said.
"I don't want to respond on what Nick said or what other players say.
"I think the most important part is to have my people around me who I can trust - people (who) exactly know what happened and that's it."
In an exclusive interview with AAP, ATP chairman Andrea Gaudenzi insisted Sinner's doping affair had been "run by the book" and said the sport will "survive" if the two-time major champion ultimately cops a lengthy ban.
Sinner overcame the fierce scrutiny after his positive tests last year when he won the US Open and ATP Finals.
He is desperate to defend his title in Melbourne, having beaten three-time runner-up Daniil Medvedev in a gripping five-set final last year.
Sinner has made small tweaks to his service motion since helping Italy achieve Davis Cup glory last November and has adopted a fresh tactical approach, eager to move forward more often to "mix up" his game.
"We made some changes, but let's see this year how it goes," Sinner said.
