Tottenham's attempts to refresh their options in defence have come under threat as sources have told ESPN that Napoli are attempting to rival the north London club in the race to sign Genoa defender Radu Drăgusin.
Spurs remain in talks with Genoa over a fee for Drăgusin, 21, who has indicated a willingness to move to north London but the situation has been complicated by Napoli stepping up their interest.
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Sources have told ESPN that Spurs plan to allow Eric Dier to leave once a suitable replacement -- ideally Drăgusin -- has been signed, with the England defender attracting significant interest from Bayern Munich.
Dier is in the final year of his Spurs contract and when pushed if he would like to keep the defender, Postecoglou said: "Eric is contracted to this football club, and he's as much in control of his destiny as anyone else."
Reports in Italy suggest Serie A champions Napoli are ready to make a player-plus-cash offer for Dragusin which could drive the asking price beyond the £20 million to £25m range in which Spurs were hoping to reach an agreement.
Talks are ongoing with a source confirming to ESPN that Drăgusin's agent is expected to hold further negotiations today and Tottenham are still hopeful of completing a deal.
Spurs are looking to sign at least one central defender this month with head coach Ange Postecoglou hoping for quick business given Cristian Romero has joined Micky van de Ven on the sidelines and is not expected to play again until next month after suffering a hamstring injury.
Van de Ven is back in training and Postecoglou has not ruled out the Dutch defender playing some part in Friday's FA Cup third-round tie against Burnley.
Asked on Thursday about the possibility of signing a centre-back soon, Postecoglou said: "It's hard to say because I don't get involved in that side of it.
"As I said leading into the window, we've got some objectives and some targets and we're working towards that.
"People behind the scenes and in charge of those areas are working towards that and my role within that is when I'm sought for guidance and clarity on which way we need to go, I provide that."