Frazier Campbell remains keen to join Hull but will not be rushed into sealing his £6million move, according to his father and agent.
Tigers chairman Paul Duffen and manager Phil Brown agreed a fee with Manchester United for the England Under-21 international three weeks ago and also reached an agreement in principle with the player over his personal terms.
But Campbell, who spent a successful spell on loan at the KC Stadium during the 2007/08 season, is still to put pen to paper having been away on international duty with England at the European Under 21 Championship in Sweden.
Reports of interest from Sunderland have put the switch in some doubt, while Campbell is still to finalise the terms of his departure from Old Trafford.
Keith Campbell, who represents his son, insists he has only held talks with the Tigers and claimed part of the delay is down to the Red Devils.
"I've spoken to two people. I've spoken to Paul Duffen and I've spoken to Phil Brown, and they're the only two people I've spoken to," Campbell senior told the Hull Daily Mail.
Asked if his son remained keen to join the Tigers in a club record deal, he added: "Definitely.
"It's just purely and simply down to Manchester United, when they sort themselves out then it's fine."
Although Hull are eager for the transfer to be finalised, Campbell will spend some time on holiday before committing his future, having only just returned from Sweden.
His father said: "There are no deadlines at all.
"Fraizer has played a lot of football and we are going to go off and enjoy the holiday, have a discussion while we're away and see where it takes us."