Sinner blocked out 'very, very tough' off-court turmoil to win Shanghai Masters
In August, the International Tennis Integrity Agency said Sinner had failed two drug tests in March but had been cleared of wrongdoing by an independent tribunal.
The tribunal accepted the Italian's explanation that the anabolic agent clostebol entered his system from a member of his support team through massages and sports therapy.
However, in September, the World Anti-Doping Agency (WADA) said it would appeal against the independent tribunal's decision and was seeking a period of ineligibility of up to two years for Sinner.
WADA's announcement came days before Sinner was beaten by rival Carlos Alcaraz in the China Open final, with the US and Australian Open champion admitting he was in an uncomfortable situation ahead of his Shanghai Masters campaign.
"This year has been very, very tough for me because of other circumstances and at points I lost a bit of my smile because I had some issues off the court, and they're still in my mind sometimes," Sinner told reporters after his win in the final.
"People think that by winning or having success you don't have any problems, but it's not true, because I'm in the situation where I'm in. Obviously, it's not comfortable, and I wish I would not be in this position where I am right now off the court.
"But you have to accept it. I feel like I'm strong when I go on the court, trying to not think about it and trying to stay focused on everything I do and give a 100% in every single match or practice."
Sinner's win over 24-time Grand Slam champion Djokovic has taken his trophy count for the year up to seven, including two Grand Slams, three ATP Masters 1000 titles and wins in Rotterdam and Halle.
This season has been the 23-year-old's most successful on tour, and when asked what had changed in the past year, Sinner said: "I feel that physically I'm ready to play for a longer amount of time at the highest level possible.
"Also mentally I'm ready to accept every tough situation on the court, and I think that's the biggest step I made forward... (I'm) trying to be mature enough to understand what's working, and I feel like that for me made a big impact this year.
"Hopefully it's going to help me also for the next year."