Maurizio Sarri says Callum Hudson-Odoi has been unaffected by the doubts over his Chelsea future but that it is “a very difficult moment” for Alvaro Morata.
Spanish striker Morata has failed to impress since a big-money move to Stamford Bridge and looks likely to leave during this transfer window.
Hudson-Odoi could also be leaving, with Bayern Munich pursuing the youngster.
But Blues boss Sarri says Hudson-Odoi has gone from strength to strength despite speculation over his future.
“I am very happy with him, because one month ago we worked with him for the defensive phase and he improved immediately,” Sarri said at a press conference.
“Now we are working with him for movements without the ball and in my opinion he is improving.
“So on the pitch we are really very happy with him because he is improving a lot in the last two months.
“I think he is in a very positive moment mentally. For the attitude, for the way he is training, I think that mentally he is in a very positive moment.”
Morata, meanwhile, is in the squad for this weekend’s game against Arsenal but is not expected to play.
“I don’t know if he will play, but he is training with us of course,” Sarri said.
“Of course for him I think it’s a very difficult moment. It’s normal for a player in January to be involved in the market.
“He’s available, but like in the last match I can try something different.”