Bayern have made no secret of their interest and Sarri doesn't think they have acted properly.
Sarri snapped: "I think that it is not professional because they are talking about a player under contract with Chelsea so they didn't respect our club.
"Then I don't know what to say I don't know the situation. I am happy with the player because he is improving, improving a lot in the defensive have.
"Now he needs to improve in some movements without the ball but he is working very well at the moment so I am very happy with the player and would like to have him in the future."