The Belgian has been a regular since completing his move to to Spurs from Ajax in 2012.
Barcelona are believed to be in the market for a new centre-back in January having failed to add to their ranks in the summer.
According to reports in Spain, Barcelona are eyeing up a move for Vertonghen, who was linked with a move to the Catalan giants before he signed on the dotted line at White Hart Lane.
Barcelona are said to have been monitoring the Tottenham man for some time ahead of a potential winter swoop, and could make him a priority above the likes of Liverpool's Daniel Agger and Chelsea's David Luiz.
They may also be hoping to capitalise on Vertonghen's perceived unhappiness at Tottenham this season.
The Belgian international has been forced to operate out of position at left-back because of injuries, something he has publicly stated he is unhappy with.
Vertonghen may also be tempted to jump ship with the wheels threatening to come off at Tottenham following their slow start to the season which culminated in a 6-0 thrashing against Manchester City last weekend.
Barcelona have been formed to deploy the likes of Javier Mascherano and Alex Song out of position at centre-back in recent months because of a shortage of natural defenders.
Carles Puyol is coping with a long-term injury, while with Mascherano also sidelined, youngster Marc Bartra has been filling in.