Maurizio Sarri wants a new midfielder for Chelsea after advising Cesc Fabregas to leave the club for the good of his career.
The Blues boss, speaking ahead of Tuesday's Carabao Cup semi-final first leg with Tottenham, insisted Callum Hudson-Odoi was "ready" for big games and that the 18-year-old's future was at Stamford Bridge.
But Sarri insisted Fabregas – at the other end of the age spectrum in Chelsea's squad – should seek to complete an anticipated move to Monaco, after the 31-year-old appeared to bid farewell to Chelsea following last Saturday's FA Cup win over Nottingham Forest.
"In my opinion, he needs to go," Sarri said.
"You know very well the situation. You know very well in this club there is a rule: the renewal of players over 30 is usually one year.
"He has an offer for two years. I don't want a very important player as Cesc unhappy.
"If Cesc will go, of course we need a replacement."
Sarri said Fabregas suffered cramp against Forest and may not be available to face Spurs, although Eden Hazard and David Luiz were among those to suggest after the match that it was the Spaniard's farewell.
The Blues boss said Fabregas had a "free day" on Sunday, refusing to confirm or deny reports the playmaker went to France to meet with Monaco.
Thierry Henry, Fabregas' former team-mate at Arsenal, is now Monaco boss.
Henry said on Monday, according to Monaco's official Twitter account: "Since I left Arsenal, we talk every two or three days and that hasn't changed in recent days. Cesc is a player who interests every club."
Ruben Loftus-Cheek is out of the Spurs fixture, with Chelsea seeking to determine the full extent of his back problem.
Forwards Pedro, Willian (both hamstring) and striker Olivier Giroud (ankle) have returned to training following injury and could be in contention to play.
Hudson-Odoi should be in the squad after providing both goals for Alvaro Morata against Forest.
The teenager has also been linked with a move, to German giants Bayern Munich, with 18 months remaining on his current contract and the offer of a new deal with Chelsea as yet unsigned.
Sarri said: "For me, he's a very important player. I think to stay here is better for him. He's an English player.
"He's very young. He has a very great future here, in England, with the national team and with Chelsea.
"We have very important players in the same position. (But) I think now he is ready.
"Sometimes he will be on the bench, as Willian, as Pedro. Now I can start to consider him at the same level (as Willian and Pedro)."
Sarri's first two losses as Chelsea boss came at Wembley, in August's Community Shield against Manchester City, and, after an 18-match unbeaten run, against Spurs on November 24.
Spurs scored twice in the opening 16 minutes and Sarri afterwards bemoaned his side's attitude.
He said his team must match Spurs' desire before tactics can be taken into account on Tuesday night.
He added: "We need to approach the match in another way, because we lost the match in the first 15 minutes. They were really more aggressive than us, more determined than us.
"Now we know very well if we approach the same there's no solution for us. I want to speak before about this, otherwise it's useless to speak about tactics."