Sinner reached all four major finals in a year when he also served a three-month doping suspension after twice testing positive for a banned substance in 2024.
Wada accepted Sinner “did not intend to cheat” and Djokovic said he believed the Italian “didn’t do it on purpose”.
However, Djokovic warned that the case would remain a “cloud” over the 24-year-old throughout his career.
“That cloud will follow him as the cloud of Covid will follow me,” said Djokovic, who was deported from Australia in 2022 because he was not vaccinated against the virus.
“Over time it will fade, but I don’t think it will disappear.”
A number of players questioned the timing of Sinner’s ban, with Djokovic adding: “There is the lack of transparency, the inconsistency, the convenience [of] the ban coming between the slams so he doesn’t miss out. It was very, very odd.
“I really don’t like how the case was being handled. You could hear so many other players who had similar situations coming out in the media and complaining that it was a preferable treatment.”