Tottenham Hotspur are reportedly growing "increasingly concerned" that they will have to sell centre-back Toby Alderweireld this summer as talks between the two parties continue.
MailOnline's Sami Mokbel reported a clause in Alderweireld's contract allows Spurs to extend his contract beyond its current 2019 expiration date, but that would then activate a £25 million release clause in his deal.
The decision to extend Alderweireld's current terms could leave Tottenham open to losing their star centre-back for significantly less than his market value.
The Belgium international is currently sidelined through injury, although the Press Association's Tom Allnutt saw a positive impact of him not being able to push for a move during the winter transfer market:
Spurs manager Mauricio Pochettino recently sought to soothe fan fear when quizzed on Alderweireld's contract situation, per Alasdair Gold of football.