Premier League clubs are watching Gelson Martins' situation at Atletico Madrid.
The Daily StarLiverpool, Chelsea, Everton and Spurs have made checks on the 23-year-old's availability.
Martins only arrived at Atletico Madrid on a free transfer this summer after cancelling his contract with Sporting Lisbon following a training ground attack.
Despite this, Gelson has played just 30 minutes of La Liga action so far this season putting Premier League teams on 'full alert'.
The Portuguese winger is valued at £30m.