Spurs have held a long-standing interest in the Belgium international, along with their north London rivals Arsenal.
It would appear as though the highly-rated centre-half will be turning out at White Hart Lane next season, with an agreement reportedly edging towards completion.
De Boer admits Vertonghen is now waiting on the 'green light' to make a move to the Premier League.
Taking that into account, he left the 25-year-old out of his squad for a pre-season exhibition game against FC Emmen.
"John has his head in London, so we sent him home," De Boer told Telesport.
"He is only waiting on a few minor details before he gets the green light."
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