Manchester United boss Mourinho wants Tottenham powerhouse Alderweireld to boost the clubâ€™s vulnerable defence next term.
Despite shipping just 28 Premier League goals last term, the Red Devilsâ€™ current crop of defenders is not up to scratch.
Question marks linger over the quality of both Phil Jones and Chris Smalling, despite both players signing for Manchester United in 2011 and 2010 respectively.
Eric Baillyâ€™s future is also uncertain, while Victor Lindelof has toiled since his arrival from Benfica 12 months ago.
And The Sun say Mourinho has now set a price tag for top United target Alderweireld.
It is said the 55-year-old views the Spurs defender as one of the best players in his position.
A club source is quoted as saying: “The manager considers the player one of the best in the world in his position.
“The club know there could be a bargain to be had. He is an unbelievable talent for the money.
“His wages certainly aren’t a problem for United. They know they can pay what he wants if they have to.
“There is a feeling Alderweireld would still like to stay at Spurs if they decide to meet with his demands.”
The Sun say United are willing to pay ÂŁ50million to sign the Belgium international.
But that may not be enough with reports previously claiming Tottenham want nearer to ÂŁ75m.
Unitedâ€™s cause may not be helped by their previous dealings with Spurs.
The north London giants were furious when Sir Alex Ferguson signed Dimitar Berbatov in controversial circumstances back in 2008.
And, since then, Tottenham have blocked United from landing the likes of Gareth Bale, Luka Modric and Danny Rose.