Manchester United scouts have watched Sporting Lisbon midfielder William Carvalho for an eighth time this season
The Portugal midfielder has been closely monitored by United for a while and was last watched during his side’s 0-0 draw with Academica on Sunday.
The 21-year-old remains in contract until 2018 with the Portuguese club but his current deal contains a release clause which could see him leave if the £37.5m stipulation is met.
Spanish pair Real Madrid and Barcelona are both believed to have also been watching the young midfielder.
Carvalho made his debut in 2011 but had to wait for his chance at the club after taking two loan spells to Fatima and Cercle Brugge, before making his breakthrough this season.
The Angola-born Portugal international then made his debut for his country in a World Cup qualifier against Sweden in November and is tipped to take a place in the squad for the finals in Brazil.
Due to his large price tag, United would hope to negotiate a cheaper deal for the player if they hope to bring him into their squad in the summer.