Jack Ross would like to keep Josh Maja for the rest of the season, but accepts it could be out of his hands if next week's deadline passes without a deal being agreed.
Maja has been offered a new contract to extend his Wearside stay and the Black Cats want a decision before the trip to Charlton Athletic next Saturday.
Should he not sign, Sunderland are then left with a difficult decision.
There is significant interest in the 20-year-old and his goals would be a major loss in the second half of the season.
Should he leave on a free in the summer, however, the Black Cats will likely receive a disappointing compensation fee.
“I suppose the consequences of a deadline passing are out of my control," Ross said.
"I won't treat him differently.
"It would possible by out of my hands even if I have a good relationship with him.
"It sounds as if I am absolving myself of any responsibility but I am not.
"Naturally, I would say keep him here if I am asked but that might not be possible.
“There’s this ongoing debate about other aspects of his game and I feel like exactly the same, I work with him every single day," Ross added.
"But to score the goals he has done in his first full season is terrific. They are not easy to come by and his goals have been invaluable this season.
"Naturally I want to keep him within the squad.
"I am also sensible enough to get the bigger picture and I bought into that when I came in. Whatever happens in the next seven days I will deal with that.
"I will deal with the consequences of whatever, and it’s up to me to find a solution to any problems."
Ross insists there has not been a change in mood behind the scenes and remains hopeful that Maja will commit.
As time passes, however, increased doubts are inevitable.
“Genuinely it’s not the case [change of mood]," Ross said.
"From a player to manager relationship I would still believe he will stay.
"As time goes on, and there’s no commitment, you have to have some doubt within it.
"I have said this to him, I will never take things personally.
"I get both perspectives on it, his and the clubs, and he knows it. When I say this is the best place for him at this club, I hope he believes that."
The situation will have a significant impact on Sunderland's January business, with Ross unlikely to recruit any new strikers so long as Maja stays.
One department he will strengthen regardless is defence.
Ross expects a loan addition in the early days of the January window.
“All being well, that will happen," Ross said.
"There are just one or two things that need tidying up but my understanding is we should have a defensive player in by the early part of the month, most likely to be a loan."