Aberdeen manager Derek McInnes insists Scott McKenna will not be sold this month following two bids from Hull.
The English Championship club returned with a second offer for the 21-year-old central defender.
But McInnes is determined to keep the Scotland Under-21 international, who has made 16 appearances this season.
"There will be a time when Scott will move on and he will be sold at some point, but it certainly is not going to be in this window," said McInnes.
"It will be when we feel he is going to be the player that he is going to be, hopefully on the back of breaking into the Scotland team and after playing 100 to 150 games for us."
Hull manager Nigel Adkins revealed his interest in McKenna after his side's 0-0 draw with Reading on Saturday.
"There has been an offer," McInnes told the club's website. "There was then a secondary offer in terms of tweaking the figures but nothing more on the down payment.
"It does not really matter. They have been told we have no interest or appetite to sell Scott. He will not be sold in January."