Mauricio Pochettino says it is up to Conor Gallagher to guarantee that he remains at Chelsea until the end of the season.
The 23-year-old midfielder has been linked with a move away from Stamford Bridge despite starting every Premier League match for which he has been available this season.
He is also currently the stand-in captain amid injuries to both regular skipper Reece James and deputy Ben Chilwell.
However, with only 18 months left on his current deal, his future is far from certain, with Tottenham and West Ham both showing interest during the summer.
Asked whether he could guarantee that Chelsea won't sell Gallagher in January, manager Pochettino said: "Look, I cannot guarantee I am going to be here tomorrow or any other thing!
"Look, in football different things can happen and it is between the club and the players. Only the player and club can guarantee it, the player more than the club because the player has one year and a half more and he can stay.
"He can say, 'yes, I am going to stay because my coach can allow me to stay and be here' and then the club has to do a negotiation, as always, to make the best decision for the club and the team."
He added: "Conor still has one year and a half on his contract with us. Of course, that is like all the players at different clubs that when you arrive at this point, you talk and take some decisions for the future.
"Of course, it is always going to be between the club and the player. At the moment, nothing to announce or say.
"The club is happy with him, he is happy here and I think at the moment there is nothing to say or announce."
Pochettino will be without 10 first-team players when Chelsea host Preston in the FA Cup third round on Saturday evening.
But Chilwell, Carney Chukwuemeka and Benoit Badiashile could all return to face either Middlesbrough or Fulham next week.
"Chilwell and Carney are not available for tomorrow, we will see for the next games against Middlesbrough and Fulham," Pochettino said.
"They are doing well and trained with the group in the last few days. We are so happy with their evolution. Benoit is going to be available next week, I think.
"[Romeo] Lavia is recovering from his injury but we still don't know when he will be back from his quad problem suffered against [Crystal] Palace.
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"Christopher [Nkunku] is not going to start tomorrow because he suffered some issues during the week but he is going to be in the squad."
Pochettino explained that Chelsea would be taking Championship opposition very seriously and warned not to expect wide-scale alterations to his team, adding: "Not too many changes.
"Playing with the circumstances of course, not going to change too much the team. You will see maybe one or two players normally not in the starting XI, but of course because we have some circumstance we need to prevent and we need to anticipate problems.
"We talk like a Premier League game, it's not because it's the FA Cup and a Championship team. Full respect to Preston and tomorrow you will see we are going to put in place a starting XI with the opportunity to perform."
