Chelsea boss Maurizio Sarri is keen to tie down veterans David Luiz and Cesc Fabregas on new deals, although he will face competition from Atletico Madrid for the latter.
The Italian is hopeful of reaching an agreement with the two players, but has conceded it will be difficult, with both pertaining contracts that run out at the end of the season, and thus able to negotiate with clubs outside England next month.
Speaking to Sky Sports about the issue, the Italian admitted: "I spoke with the club about this one month ago. I know very well that it's not easy, but I think we can do a new deal for both.
"They are very important players for us. It is very difficult to find a centre-back for this level and it is very difficult to find a centre-midfielder technically like Fabregas, so I think they have to stay with us.
"The deal is very difficult for this reason [both players are over 30 years of age]. The club wants a short contract and the players want a long contract. It is difficult for this reason but I think we can find a solution."
While the Brazilian defender has returned to the starting XI fold following his falling out with Antonio Conte, Fabregas has comparatively struggled to get a look-in under Sarri, with just 48 minutes in the Premier League so far, and may well be tempted by pastures new.
One such option could be Atletico Madrid, with Mundo Deportivo reporting that Diego Simeone's side are very much interested in attaining the 31-year-old on a free next summer in order to 'shore up their midfield'.
Meanwhile, in more positive news for Chelsea fans, Sarri also confirmed his desire to keep academy graduate Ruben Loftus-Cheek in west London: "At the moment he is very important for us. He had some problems to understand what I wanted, but now he is improving and in the last two matches I was really very happy with him.
"I want him to stay with me, with us, so I think there is no chance (of him leaving)."