The Dutch ace moved to the Camp Nou in the summer of 2019 from Ajax and has become one of the most important players at the Blaugrana.
As highlighted by Diario AS, the midfielder has been rated as having a €90m transfer value by Transfermarkt, who gauge player values in the market.
That sees him valued at €10m more than the next highest valued players on the list, including his Blaugrana teammate Lionel Messi, alongside Atletico Madrid pair Joao Felix and Marcos Llorente.
The other feature in Barcelona news sees midfielder Pedri ranked in the top 10 with a value of €70m, which is the same as Real Madrid duo Raphael Varane and Casemiro, along with Atleti goalkeeper Jan Oblak, with Fede Valverde of Madrid ranked at €60m.
De Jong has scored nine goals in 93 appearances for Barca.