Spurs have been encamped in America over the past few weeks on their pre-season tour.
Modric refused to travel to the United States, something he was fined for, and has been training on his own at Spurs’ training ground.
Real Madrid are in talks with Spurs, but reports claim that Tottenham are holding out for £40million – even rejecting the offers of players in exchange with the likes of Ricardo Carvalho and Nuri Sahin mentioned.
Villas-Boas admitted after their final tour game with New York Red Bulls that they would look again at Modric’s situation.
“Luka is now doing double sessions on his own and when we get back to London we will give players time off and after that we will decide what is best for Luca to do,” he told Sky Sports News.
Villas-Boas says Modric is now behind the rest of the Spurs squad in terms of fitness, due to the fact he did not go on tour.
“He is a Tottenham player obviously and he has to be in good mental state to return to training as his colleagues are a step above and we will have to work on a programme for him to work on his fitness,” he added.