The world number one looked to have avoided a ban after testing positive for the banned substance clostebol but is not "comfortable" with the World Anti-Doping Agency's (WADA) appeal against the verdict that could see him suspended from the sport for up to two years.

Sinner said: "I'm still surprised.

"But I will collaborate like I did before. I had three hearings in which the three hearings went all my way, which was good. But now let's see. But I'm very confident that it comes out very, very positively. I would be very, very surprised if it would be the opposite side.

"But it's not in a situation where I feel comfortable in, that's for sure, because I thought it was over. And now once again. So it's not easy."

Sinner put the ongoing controversy aside as he reached the China Open final where he lost to Carlos Alcaraz and the two-time major champion says that he and the Spaniard are like "fire and ice" in terms of their style of play.

He told the ATP: "I feel like off the court we are quite similar on the court we are different.

"He is the one who brings the firepower and the hot shots, he involves the crowd. He is a bit different. I am more like the solid player, quite calm. So it's like fire and ice a bit. But it's a nice combination."