De Ligt, meanwhile, is a 19-year-old centre-back allegedly deemed by Spurs earlier this year as a successor to Toby Alderweireld in the heart of the team's defence, according to the Evening Standard.
A number of other clubs are also thought to be in the running for the two players, with Goal.com tipping Manchester City to make a move for De Jong.
In a development sure to alarm Spurs fans, the latest comments from Netherlands legend Ronald de Boer could potentially scupper Tottenham's hopes of landing the duo.
The former Ajax star has urged De Jong and De Ligt to consider a switch to Barcelona as their playing ethos is similar, but failing that, they should consider Pep Guardiola's charges.
“I advise them to sign for Barcelona, or if not, for Pep's Manchester City," the Dutchman told Spanish outlet Esports COPE.
“Ajax’s style is the same as Barca’s, they could adapt quickly. I would also advise them to go to Barcelona because the club is in my heart.”
With such a glowing recommendation from one of Dutch football's best players of recent times, could these comments sway De Boer's young compatriots away from north London?