Chelsea, who won last week’s first leg game in London 3-0, trained at the stadium on Wednesday.
“The pitch is not good and I think that it’s really dangerous to play any football here. It’s really very dangerous for injuries,” Sarri told reporters.
“I don’t know the reason, probably winter, because I played here two years ago and the pitch was wonderful (but it is now) very, very dangerous.”
The NSC Olympic Stadium hosted last season’s UEFA Champions League final between Real Madrid and Liverpool, which the Spanish side won 3-1.
Sarri was in charge of Napoli when the Italian side beat Dynamo 2-1 at the stadium during the 2016/2017 UEFA Champions League group stages.
Chelsea coach Sarri also criticised UEFA for not paying more attention to player welfare.