Sarri, who also revealed Victor Moses will miss the PAOK clash due to a back injury, admits he has some concerns about Hazard due to his recent struggle for form and fitness.
Speaking at a news conference on Wednesday, Sarri said: "The last problem is Moses. I spoke with the doctor 10 minutes ago and Moses has a back problem. I think he will be not able to play.
"Then, Hazard of course, is not a serious injury. I think he will not be able to play but I think we will be able to recover him for the next Premier League match."
When asked about Hazard's recent form, which has seen him go five games without a goal in all competitions, Sarri said: "I am worried because 25 days ago he had a back injury, now the ankle.
"I think he lost a lot of training, so it's normal that he is not at the top of physical condition. He has one week of training and a couple of matches.
"This week, it's useful for him to have training, and then we'll see. Of course, I think he cannot play 10 matches in 29, 30 days, so sometimes he has to rest."
Chelsea head into the match needing only a draw to guarantee they will top Group L and Sarri has promised to make some changes to the team that lost 3-1 to Tottenham last weekend, especially with a packed December schedule on the horizon.
"In December, we have to play 10 matches, so I think now we need to change," he said. "We had two targets in this competition: the first is qualification, and this target is taken. The other one is to win our group. For this, we need one point, but we cannot think to play for one point, or it is easy we lose the match. But, of course, we can do this if we change seven, eight players.
"I have to think through everything. Saturday, we played very badly, without determination. We lost a match after 110 days, I think, so the team did well generally but we have to understand why we played against Tottenham without determination, it's not normal. [Thursday] is important for us because I want to see a reaction. I want to see we learned our lessons."