If Manchester United want to sign Saul Niguez, 23, this summer they must pay the full release clause of £54m according to reports in Spain.
The Atletico Madrid midfielder has been in exceptional form this season, with interest from across Europe from United, Juventus and Manchester City.
Despite losing the Champions League final last the week, the Atletico playmaker was one of the stand out players. These kind of performances are what attracted Manchester United and they are now prepared to make a formal bid.
New United boss Jose Mourinho made Saul one of his top targets when presenting the board with his transfer list last week upon confirmation of his appointment.
It will now be left to the United hierarchy to get the deal over the line before Saul links up with his Spanish team mates for the European Championship.
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