David Luiz and Danny Drinkwater will not be available when Chelsea visit West Ham United on Saturday (9 December) with Antonio Conte adding that he will need to check the fitness of other unidentified players before deciding on his starting-line up.
Luiz has not played a game since the 4-0 win over Qarabag in the Champions League on 22 November due to a knee injury.
Meanwhile, Drinkwater played the full 90 minutes last weekend in the 3-1 victory over Newcastle United before making Conte's bench for Tuesday's draw with Atletico Madrid.
Both players will certainly miss the upcoming derby at West Ham but Conte suggested two or three more are also doubtful.
"David Luiz is out. Danny Drinkwater is out, because he's sick. This is the third day with a fever," Conte said in a press conference ahead of the trip to east London.
"Then we have to check a couple of situations, then to make the best decision for tomorrow's game against West Ham. I have to check the physical condition. After all these games it's normal to check a player could be tired. We must pay great attention to try to make the best decision, to try to find the right solution."
Pressed on which other players are doubtful, the boss added: "I like to keep this situation, not secret, but I don't want to tell who are these two players or three players."
Luiz's spell on the sidelines has sparked speculation about his future at Chelsea amid reports linking the Brazil international with a January move to Real Madrid.
It has been claimed that the relationship between Conte and Luiz is under strain since the defender was surprisingly left out of the squad for the 1-0 victory over Manchester United on 5 November.
But asked about those reports, Conte said: "I think now this is not the right moment to speak about this. Now there is a lot of games before the transfer window. Now I think is not the right moment to speak about this. Now this is not important."
Hazard's long-term future at the club has also come under scrutiny with reports claiming Real Madrid are also monitoring his contract situation ahead of the summer transfer window.
Chelsea are trying to tie him down to a new long-term contract but Conte was also coy when asked about the possibility of losing Hazard in the summer.
"Now I repeat: it's important to be focused on this moment. Then when there is the right moment, I try to answer this question," the Chelsea boss added.
Conte meanwhile was delighted to see Hazard and N'Golo Kante in the top 20 of the Ballon D'or rankings revealed on Thursday which saw Cristiano Ronaldo claiming a fifth accolade.
"Eden is a young player and he has the potential to improve his place in this table. At the same time, I like to repeat: you have to win trophies if you want to reach the best. A top player must have this ambition," Conte said after the Belgium international came 19th with Kante finishing eighth.
"To finish eighth in the Ballon D'Or table for a player like Kante, with these type of characteristics, is not easy," Conte added of his French midfielder. To finish eighth is a great result for N'Golo. I am proud for him. All the people understood the capacity of this player. He is a fantastic player, and for me in his role he is one of the best in the world."