Antonio Conte has admitted that he is desperate to keep Eden Hazard and Thibaut Courtois at Stamford Bridge as Chelsea cannot afford to lose their best players.
Both men have been linked with a switch to Real Madrid, who are looking to strengthen at both ends of the field across the next two transfer windows.
Further doubts regarding Hazard's future emerged on Friday, with the Belgian's father claiming that the offer of a new contract has already been knocked back.
Chelsea boss Conte acknowledges the importance of adding to his squad in the winter window, however, rather than losing star names to rival clubs.
"You are talking about two important players for us," he told reporters. "It will be very important to continue with these types of players especially for your ambition to try to compete for something important. It is important to try and improve your team, to strengthen and not to sell the best players."
Asked about Courtois's situation, with the goalkeeper's family currently based in the Spanish capital, Conte added: "When you are in a great club and you trust in the project, you want to stay. I think the family is not a problem.
"This is a private conversation between the player, the agent and the club. If you ask me, for sure I hope he stays. Hazard? My answer is always the same. This is a private conversation between the club and the player and the agent of the player.
"The same picture is for Eden. I am proud to have him in my squad and to work with him. He is a good guy and he has a lot of space for improvement and to become one of the best players in the world. But on this issue, I repeat, this must be a private conversation."
Outcast defender David Luiz has also been touted with a move to Spanish and European champions Real Madrid.