Real Madrid are one of a number of clubs monitoring the situation of Tottenham defender Toby Alderweireld, say reports.
The Belgium international will not travel to Turin with the Spurs squad to face Juventus this week despite announcing his return to fitness.
A report in The Telegraph outlines this illustrates underlying friction between the defender and the club which has alerted several leading European clubs, including Madrid.
The former Atletico Madrid defender has a current deal at the North London club until June 2020 but reports states that includes a £25m release clause which can be triggered from 2019.
Manchester City and Chelsea are two other clubs who have been linked with the highly-rated defender.