Tottenham reportedly sent a scout to attend a match between Porto and Estoril on Wednesday to watch long- term target Ricardo Pereira.
Despite the emergence of Kieran Trippier at the back end of last season, Spurs are apparently intent on strengthening the position made weaker by Kyle Walker's departure.
The former Burnley player ousted Walker from the starting XI for the last few games in 2016/17, and some fans were keen to see Trippier given the chance to shine again as first choice in the new season.
But Portuguese outlet A Bola, via Sport Witness, say the club sent an official to keep tabs on Pereira, who has been on their radar for some time.
23-year-old Pereira has spent the past couple of seasons on loan with French side Nice, and excelled at both right and left-back.
Apparently Spurs made a €15m offer to Porto for the player back in June, but that was some way short of the club's €25m valuation.
Daniel Levy is expected to come back in with a new offer for the player following the scout's feedback from Wednesday night's match.
Spurs fans are desperate to see some incomings after watching Manchester City, United, Chelsea, Liverpool, Arsenal and even Everton all strengthen - the Lilywhites have also been linked with a move for Davinson Sanchez of Ajax.