Jannik Sinner batted away a question about his girlfriend while admitting his now-closed doping case affected him negatively before winning the US Open

Jannik Sinner has refused to answer a question about kissing his girlfriend after Sunday’s US Open final victory. The World No. 1’s second Grand Slam title of the year came weeks after news of his doping violation became public, which he says made him “sick” and resulted in “sleepless nights”.

Jannik Sinner has shed light on the “sleepless nights” he endured during the US Open (Image: Getty)

Sinner, 23, began the US Open under a shroud of controversy as it was revealed just days prior that he’d twice tested positive for the banned substance clostebol in March. The Italian tennis star was allowed to continue playing after an independent tribunal ruled he “bore no fault or negligence”, having successfully argued that the tests were the result of contamination from his then-physio.

His doping saga finally came to a head this week after the The World Anti-Doping Agency did not appeal the decision. But the controversy did not come without taking a toll on Sinner at the US Open, where he emerged victorious for the first time.

Jannik Sinner won the US Open and was found to have “bore no fault or negligence” for two anti-doping violations. (Image: Getty)

Talking about the impact of his doping controversy, Sinner told Ubitennis: “Since the news came out, I’ve been sick, I haven’t slept, I’ve had many sleepless nights and then when there’s tension involved it’s even more difficult, but it’s made me grow and that’s why I’ve won so many games.”

Sinner’s celebrations after beating Taylor Fritz 6-3 6-4 7-5 were notably subdued. The toll of recent days was evident as he merely put his arms in the air.

It was only when he approached his player’s box that he displayed emotion, hugging members of his team, as well as girlfriend and fellow tennis star Anna Kalinskaya. He kissed the Russian – something which he was also quizzed on.

Jannik Sinner girlfriend (Image: Getty)

The Ubitennis interviewer asked: “Jannik, forgive me for asking this. Italians want to know the first name of your aunt to whom you dedicated your victory. And then, you are aware that the whole world saw the kiss (with Kalinskaya), are you happy about that?”

But the two-time Grand Slam winner batted away both questions, saying: “I don’t want to answer one or the other. It’s a family thing.” Sinner’s doping scandal and his relationship with Kalinskaya have been targetted by his tennis rival Nick Kyrgios recently.

Kyrgios, who is currently out injured, called for Sinner to face a two year ban and has continued to take aim at his doping case. While fans speculated whether Kyrgios holds any bitterness because Sinner is now dating his ex, Kyrgios on Saturday replied to an old photo of the happy couple with the cryptic message: “Second serve.”

Kyrgios wasn’t tagged in the post and the tweet did not contain any text but he still managed to find the old snap. The user quickly deleted it but screenshots popped up all over social media as the Australian faced backlash.