The midfielder is expected to depart White Hart Lane this summer following the club's failure to qualify for the Champions League.
La Liga champions Real Madrid are currently leading the race for the Croatia international, but face stiff competition from big-spending Paris Saint-Germain and Premier League rivals Manchester United.
Villas-Boas, who replaced Harry Redknapp as Spurs head honcho last month, confirmed that three teams are interested in Modric, but stated the 26-year-old will only be sold should they meet the £35 million asking price.
"It's exactly as we stand," the 34-year-old said following the club's 2-0 win over Stevenage on Wednesday night.
"There has been continuous interest from three different clubs and I think it's important for Tottenham to hold on to their rights.
"I have spoken openly about Luka's situation and the situation will continue exactly as it is until the chairman feels that the price is right."
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