Spurs defender Jan Vertonghen faces a race to be fit for the start of the season after injuring his ankle in their 3-1 loss to Sunderland in Hong Kong. A Tottenham side already without Gareth Bale -- also injured -- lost the influential Belgium international shortly after he came on as a substitute when he fell awkwardly on the wet surface. The friendly, part of the Barclays Asia Trophy, had been delayed 30 minutes because of torrential rain at Hong Kong Stadium. \"He might have sprained ligaments in his ankle so we obviously need the MRI to know the full extent of the injury,\" Spurs boss Andre Villas-Boas said. \"He has some range of movement, which gives us some indication that probably it may not be too long.\" Asked if Vertonghen, a key man in the Tottenham defence last season, would be back for the start of Spurs\' season on 18 August, he added: \"Depends on the extent (of the injury) from the MRI. \"I think because of the range of the movement that he has I think we have the possibility he will be back for the start of the season.\" The Portuguese conceded that he had been concerned beforehand about the state of the pitch, which was heavily waterlogged in patches and had players slipping frequently. \"The choice of the venue is this one and the weather is unpredictable. The pitch is what it is and has always been like this in this trophy. It isn\'t great but nobody is going to change it for next time. \"Obviously the conditions are extremely poor and the players are vulnerable to this type of situation.\" Tottenham took the lead in the 28th minute through a heavily deflected shot from Gylfi Sigurdsson that wrong-footed Vito Mannone, the new signing from Arsenal. Sunderland equalised minutes later when midfielder Cabral, another new signing by manager Paolo Di Canio, capitalised on a mistake by Tom Huddlestone to skip through the centre of the Spurs defence and slot the ball past Heurelho Gomes. Former Manchester United defender Wes Brown put Sunderland 2-1 up with a thumping header from a corner before sub David Moberg Karlsson put the game out of reach late on. Both teams started with strong line-ups, before making several changes after the break. Spurs started with Clint Dempsey and Emmanuel Adebayor up front, meaning England striker Jermain Defoe had to be content with a place on the bench. Sunderland gave a start to new signing and Italy international Emanuele Giaccherini, and he impressed with some neat touches on the left wing. Source: AFP