Maurizio Sarri believes Cesc Fabregas should leave Chelsea but does not know if the midfielder is close to completing a move to Monaco.
The 31-year-old is expected to join the Ligue 1 side this month, according to Sky sources, and is understood to have flown to Monaco to finalise the move.
Fabregas' Chelsea contract expires at the end of the season, and the Blues have a policy of only offering players over the age of 30 one-year extensions.
Monaco are understood to be offering the Spaniard a two-year deal, and Sarri said: "I can say only my opinion. I don't know the decision of the club. In my opinion, he needs to go.
"You know very well in this club there is a rule - the renewal of players over 30 is usually for one year. He has an offer for two years. I don't want a very important player as Cesc not happy."
With Fabregas set to end his four-and-a-half-year spell at Stamford Bridge, Sarri reiterated his desire for Chelsea to sign a replacement, but refused to be drawn on their reported interest in Cagliari's Nicolo Barella.
The head coach said: "I don't want to speak about players of other teams.
"If Cesc will go, of course we need a replacement. Now with the midfielders we are in trouble."
Club captain Gary Cahill is another experienced player who has found himself on the fringes of Sarri's team this season and is reportedly attracting interest from Fulham.
The 33-year-old was left out of the squad for the FA Cup win over Nottingham Forest on Saturday, and Sarri admitted Cahill was considering his future in west London.
"At the moment I want to understand the situation - if he wants to go or not," said Sarri. "At the moment his mind is not completely involved in our situation, so we need to wait.
"For Cahill the situation is different because we have (Ethan) Ampadu, so we don't need a replacement."