Maurizio Sarri has told Eden Hazard that he should leave Chelsea "if he wants to go".
Hazard's contract expires in 18 months' time, with the Belgium playmaker's future likely to be a major summer topic.
The 28-year-old has previously spoken of his daily quandary over whether to commit to Chelsea or seek a "dream" move to Real Madrid.
Sarri repeated his oft-voiced wish for Hazard to stay, but says the situation contrasts with Callum Hudson-Odoi's.
Chelsea have no intention of selling Hudson-Odoi now or in the summer amid interest from Bayern Munich, with Sarri telling the 18-year-old winger to commit to the club, "his home".
However, the former Napoli boss said of Hazard: "The situation of Eden is different.
"Eden is 28. If he wants to go, I think he has to go.
"Of course, I hope the opposite. I hope he wants to stay here.
"He has the potential to be the best player in Europe at the moment.
"Sometimes he's happy with something less. It's my job to improve him and put him in a position to do his best."
Sarri had hoped to make two signings this month. Only Gonzalo Higuain has arrived so far, on loan from Juventus, and the head coach is keen to recruit a replacement for Cesc Fabregas, who has left for Monaco.
Higuain is likely to make his Premier League debut at Bournemouth, alongside Hazard.
Additional reporting by rhe Press Association.
