Tottenham will trigger the extension clause in defender Toby Alderweireld's contract, but have also included a £25m release clause, manager Mauricio Pochettino says.
The Belgium international's current deal runs out next year but the club has an option to extend it until 2020.
The release clause of £25m will apply up to the last two weeks of the summer transfer window.
Pochettino said on Thursday: "It is the same situation as Jan [Vertonghen]."
Spurs announced earlier in December that the club had extended Vertonghen's contract until 2020.
The Belgium defender is back in training after a thigh injury and is due to return in January.
Alderweireld joined Spurs in July 2015 from Spanish club Atletico Madrid. He has made 17 league appearances this season for Pochettino's side.