Tottenham are refusing to relax their stringent wage structure as fears over the future of key defender Toby Alderweireld grow. The central defender's importance to Mauricio Pochettino's side has been underlined in recent weeks, Spurs registering one Premier League win in four in his absence from a hamstring injury. And concerns are growing that Tottenham could be forced to sell Alderweireld this summer with talks over a new deal at deadlock. The former Atletico Madrid defender earns £50,000-per-week - a low amount in relation to players of his quality in the Premier League. At the age of 28, Alderweireld knows this could be the last big contract of his career and is looking for a deal north of the Tottenham's current £110,000-per-week wage ceiling. As it stands, though, Spurs are unwilling to meet Alderweireld's demands but Tottenham still hope to make a breakthrough before the summer.