Tottenham Hotspur are believed to be concerned over the future of their star defender Toby Alderweireld, as the club remain determined not to compromise their strict wage structure.
The north London club could see the talented Belgian leave in the summer transfer window, as his rise in footballing stature is certain to trigger a demand for a more lucrative contract.
As reported by the Daily Mail, Spurs have struggled without the 28-year-old in recent weeks, winning just one Premier League match in four since he picked up a hamstring injury against Real Madrid last month.
The north Londoners are thought to have offered Alderweireld a new contract, but the relatively low offer on the table has seen the two parties hit deadlock.
The former Ajax youth player is on £50k per-week, and he will be looking to double his existing pay packet if he is commit to a long-term future with Mauricio Pochettino's men.
Alderweireld's contract is set to expire at the end of next season, and it remains a tricky situation for Spurs as extending his existing £50k contract by 12 months would activate a £25m release clause.
The advantage is with Alderweireld, who can hold off from signing a new contract in the hope that Spurs are pressured into offering him a lucrative deal, warding off potential suitors.
Manchester City and Barcelona are long-term admirers of the Belgian international, who could leave Spurs in pursuit of trophies if they fail to win silverware this season.
Alderweireld will face off against a number of his Spurs teammates in the summer, as Belgium have been drawn in England's World Cup 2018 group alongside Panama and Tunisia.
Harry Kane, Harry Winks, Kieran Trippier, Eric Dier, Dele Alli and Danny Rose could all be named in Gareth Southgate's World Cup squad, as Spurs' strong English contingent continues to grow.