Brighton signed free agent Adam Lallana on the first day Monday of the summer transfer window after the English Premier League winner was released by Liverpool.
Vertonghen, who has made 315 appearances for Spurs in all competitions since arriving from Ajax Amsterdam in 2012, has struggled for playing time this season under Portuguese boss Jose Mourinho.
Tottenham have enjoyed four successive seasons in Europe’s premier club competition and reached last year’s final, losing 2-0 to Liverpool in Madrid.
Apart from the news of Vertonghen, Tottenham said goalkeeper Michel Vorm also has signed an extension to his deal, while left back Danny Rose will stay on loan at Newcastle for the rest of the season.
Coronavirus Outbreak: Free agents will be a lot more coveted by cash-strapped clubs after season ends, says Tottenham's Jan Vertonghen
Tottenham Hotspur defender Jan Vertonghen says that players who are free agents when the season ends will be coveted more than others as clubs look to rebound from the financial crisis caused by the COVID-19 pandemic.
Premier League: Tottenham Hotspur player Jan Vertonghen's family robbed at knife point, says media report
Four men wearing balaclavas forced their way into the house while Vertonghen’s wife and children were inside. Vertonghen himself was with the Spurs team in Germany on Champions League duty against RB Leipzig.
Failing to beat relegation-threatened Watford is another blow to Tottenham's hopes of qualifying for the Champions League after reaching last season's final
Premier League: Tottenham Hotspur do not have time to 'sit and cry' about injuries, says manager Mauricio Pochettino
Tottenham lost goalkeeper Hugo Lloris to a long term elbow injury, with the skipper undergoing surgery earlier this week, while midfielder Erik Lamela and defender Jan Vertonghen are sidelined with hamstring injuries
Premier League: Players still committed to Tottenham cause says manager Mauricio Pochettino after Bayern defeat
Pochettino, in his sixth season at the club, pointed out that the Bayern disaster came just three days after last season's Champions League finalists had battled to beat Southampton with 10 men
Champions League: Tottenham defender Jan Vertonghen 'ashamed' after heavy 7-2 loss to Bayern Munich, calls upon fans for support
But Belgium international Vertonghen believes Tottenham can turn their fortunes around with Saturday’s league clash at 16th-placed Brighton & Hove Albion
League Cup: Mauricio Pochettino admits Tottenham squad is 'unsettled' after shock defeat to fourth-tier Colchester
Pochettino's Tottenham were beaten 4-3 on penalties against Colchester after being held to a goalless draw by a club 71 places below them, with Christian Eriksen and Lucas Moura both missing during the shoot-out.
Premier League: Full-back Serge Aurier committed to Tottenham despite pushing for move in summer transfer window
Aurier said last week that he would have liked to have moved on from Spurs but instead made his first appearance of the season and was involved in the build-up for two of the goals in the 4-0 romp over Crystal Palace on Saturday
Premier League: Christian Eriksen happy to stay at Tottenham Hotspur, says manager Mauricio Pochettino
Mauricio Pochettino insists Christian Eriksen is happy to stay with Tottenham after the Denmark midfielder failed to get a move during the transfer window.
Euro 2020 qualifiers: Kevin De Bruyne best playmaker in the world, says Belgium coach Roberto Martinez after Scotland win
Belgium coach Roberto Martinez has hailed Kevin De Bruyne as 'the best playmaker in the world' after he starred in their 4-0 win over Scotland.
Premier League: Arsenal look to gain upper hand, buck the trend against depleted rivals Tottenham Spurs
The balance of power between the rivals has swung the Spurs' way over the past three seasons as they have become north London's Champions League regulars
Mauricio Pochettino has frozen out Belgian defender Jan Vertonghen for the opening two games of the Premier League season, while Kenya midfielder Victor Wanyama is reportedly set to be sold.
Champions League: Harry Kane could be fit for Tottenham Hotspur's final against Liverpool, says Mauricio Pochettino
Tottenham Hotspur manager Mauricio Pochettino has said Harry Kane is in a 'very positive situation' and could be fit to face Liverpool in the Champions League final.
Champions League: Lucas Moura's hat-trick breaks Ajax hearts and propels Tottenham Hotspur into first final
Tottenham Hotspur reached the Champions League final for the first time in their history as a Lucas Moura hat-trick saw them come back from the dead to beat Ajax.
Champions League: Mauricio Pochettino's Spurs need to counter Ajax's possession-based game with patient play
For Mauricio Pochettino's Spurs, the key to unlocking the Ajax puzzle might well be to not try and play the game they want you to.
Champions League: Tottenham manager Mauricio Pochettino open to change in football's concussion protocols
Mauricio Pochettino said he was open to a change in football's concussion protocols as Tottenham wait for an update on the health of Jan Vertonghen.