Modric, who left Spurs this summer, today urged Bale to come and join him at the Santiago Bernabeu: "I know Gareth has a big dream of winning the Champions League and Madrid would be a great club for him to achieve it."
Bale himself has admitted he would like to play abroad at some stage in his career, but Villas-Boas is keen to hang on to the 23-year-old, who has been in sensational form this season.
The Tottenham manager also took a swipe at the Croatian midfielder for meddling in Tottenham's affairs, insisting he should be more worried about Real Madrid's current poor form than the future of Bale.
"I think he should focus more on his club than ours," Villas-Boas told a press conference.
"He has to worry about (Real's) game against Atletico Madrid and about getting in to the quarter-finals of the Champions League
"Obviously Modric is aware of Gareth's performances because of his love for Tottenham and the fact that he is very connected with him and this football club, but it's completely impossible (for Bale to leave)."