Chelsea head coach Maurizio Sarri says Callum Hudson-Odoi must remain loyal to the club who have nurtured him to become one of the best young players in European football.
Chelsea have no intention of selling Hudson-Odoi now or in the summer, with Sarri telling the 18-year-old winger to commit to the club, "his home".
Sarri, though, refused to guarantee game time to a player who has played for Chelsea since the under-eights.
"If you are one of the best young players in Europe, maybe the academy helped you," Sarri said.
"He will become one of the best in Europe also in another team, but he has to respect the work of the academy coaches.
"I think he'll be the future of our club. He will be the future of English football."
Hudson-Odoi is out of contract in June 2020 and has been linked with a £35million move to Bayern Munich before Thursday's transfer deadline.
Chelsea on Monday reportedly turned down a transfer request from Hudson-Odoi, with Sarri reiterating the club's stance on Tuesday.
Sarri said: "It's not easy to keep these young players. Every big team here in England has the same problem.
"He is of course one of the best 18-year-old players in Europe, so it's very, very difficult. The club told me he's out of the market for sure and probably he will be out of the market in July."
For Hudson-Odoi to stay into the 2019-20 season it would seem Chelsea must persuade him to sign a new contract.
Sarri insisted that is not his remit and refused to promise match action.
Speaking ahead of Wednesday's Premier League clash at Bournemouth, when Hudson-Odoi is likely to be on the substitutes' bench again, Sarri added: "It's impossible to promise him that he will play every match, because it depends on the situation."
Sarri and his assistant Gianfranco Zola have been at pains to point out that few 18-year-olds have as many appearances as Hudson-Odoi this season. He has made 11, but not yet started in the Premier League.
The 60-year-old Italian cautioned Hudson-Odoi against believing the opportunities will be better away from Stamford Bridge.
"Here, I think, it's his home," Sarri added.
"We will be patient with him because he's a boy from the academy.
"I don't know if, at another club, people would be patient with him after five, six matches.
"It's very difficult to go to another country and adapt immediately or play very well immediately. It's better for him to try and improve here."
Eden Hazard's contract also 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 Hudson-Odoi's.
The former Napoli boss said: "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.