Juventus striker Nicklas Bendtner could be sidelined for up to three months after damaging his leg against Cagliari on Wednesday night.
The on-loan Arsenal forward was forced to leave the pitch before half-time in a 1-0 Coppa Italia victory and medical tests revealed the extent of the injury.
A statement on juventus.com read: "Nicklas Bendtner has undergone an MRI scan and ultrasound that have revealed a lesion on his left adductor tendon.
"The prognosis will become clearer after further examinations which the Danish striker will undergo in the coming days."
Bendtner has struggled to make an impact for the Italian champions - failing to score in eight appearances - but his protracted absence will leave the Serie A leaders light on numbers up front, with only Fabio Quagliarella, Mirko Vucinic and Sebastian Giovinco available.
There was better news on midfielder Arturo Vidal, who complained of pain in his right knee during the game, with an MRI scan revealing light bruising.
Vertonghen joined Spurs from Ajax this summer and has gone on to become a fans' favourite after a series of excellent displays for Andre Villas-Boas' team.
The Belgian started his White Hart Lane career as a centre-back but soon moved over to left-back - the position he plays in for his country - after an injury to Benoit Assou-Ekotto.
Gunners manager Wenger, who is under pressure after Arsenal's poor start to the campaign, was interested in signing Vertonghen, but the 25-year-old instead opted to move to the Gunners' north London rivals after it became clear that the Frenchman wanted him to play in midfield.
"(Arsenal's interest) was concrete, but they wanted me to be a controller in the midfield, an Emmanuel Petit-type," Vertonghen told Dutch website NUsport.
"I'm not afraid of competition, but the overall picture of Spurs appealed to me more."
Spurs manager Villas-Boas initially moved Gareth Bale to left-back following Assou-Ekotto's injury, but Vertonghen has been a more effective solution during the Cameroonian's absence.
With Assou-Ekotto now back in full training following his three-month layoff, Vertonghen looks set to return to the heart of the defence, much to his delight.
He added: "Ultimately, I just came to play at centre back.
"Gareth Bale had to play left back, but it did not work so he pushed forward and I moved to full-back.
"I see myself still as a centre-back. I'm not agile enough to play against players like Nani and (Raheem) Sterling."
Villas-Boas, meanwhile, says any new recruits he adds in January must subscribe to his and Tottenham's attacking philosophy.
Speaking in a question and answer session on Twitter, the Portuguese, who has been linked with moves for Joao Moutinho, Fernando Llorente and Willian, said: "The players we are trying to bring in and have here also embrace that philosophy which we want to carry into the future.
"(Being at Spurs) is great because of the philosophy of the club want to implement, what I think about football and the way we should play.
"I think we should have a go, play well and be open."
Despite last weekend's defeat at Everton, Villas-Boas' team go in to Sunday's game against Swansea in fifth place, just three points behind Chelsea.
The 35-year-old, who lasted just under nine months in charge at Stamford Bridge, has been pleased by his start to life at White Hart Lane.
He said: "I have encountered a tremendous group of people, staff & players. (It was) important to get (a) positive response, which we have had since we arrived.
"It has been an exciting five months and we hope we can keep doing well in order to repay the confidence given to us from the beginning."
Wycombe, meanwhile, have announced that Spurs goalkeeper Jordan Archer has extended his loan spell with the npower League Two side until the end of the season.
