The Catalan club have been tracking both players for months and according to Mundo Deportivo , the idea was to sign the pair in the summer of 2019 as quality replacements for Gerard Pique and Sergio Busquets in the long term.
However, with half of Europe's elite clubs also interested, circumstances may force Barca to move faster in order to avoid missing out on both De Ligt and De Jong.
The Blaugrana looked at the possibility of bringing in De Ligt in the winter window, but Ajax were not willing to dispense with the centre-back in the middle of the season and Barca signed Yerry Mina instead.
On top of that, De Ligt was also keen to continue gaining experience as a starter and that is something he would not have received regularly at Camp Nou. So Barca would prefer to wait another year before bringing in the teenager, who they believe would be an excellent replacement for Pique, already 31 years old.
Nevertheless, that option now appears complicated because De Ligt has asked to leave Ajax this summer, according to Dutch newspaper De Telegraaf .
The newspaper reports that the Amsterdam outfit would only let the defender leave for a fee of €55 million (£49m/$66m), a figure that could be prohibitive to Barcelona, with president Josep Maria Bartomeu revealing recently that the club will have €60m (£53m/$72m) to spend on transfers this summer before player sales are factored in.
Barca want to bring in Antoine Griezmann from Atletico Madrid this summer and the France forward's release clause is set at €100m (£88m/$120m), which is likely to mean there will be less money to strengthen elsewhere.
De Jong's situation is similar. He is seen by Barca as a player who can rejuvenate their midfield. This summer, Andres Iniesta is leaving, while Ivan Rakitic is 30 and Busquets will be too in a couple of months. However, the club are happy to wait until 2019 for De Jong as they believe the team currently has more pressing needs.
One of those is the €30m (£26m/$36m) move (plus €9m in variables) for Brazilian midfielder Arthur Melo , with €4m already paid to ensure he does not sign for any other club. Meanwhile, Philippe Coutinho was signed in January, Paulinho arrived only last summer, Carles Alena will be promoted to the first team and Andre Gomes is also still at Camp Nou.
The Portuguese international may yet be sold this summer and that could facilitate a move for De Jong, but Barcelona will need to act quickly to avoid missing out on the midfielder and also his Ajax team-mate De Ligt.