The Netherlands were knocked out at the Round of 32 stage, after a penalty shootout loss to Morocco, with De Jong playing several matches at the tournament with a bandage on his knee.
Barca requested De Jong return early from his summer break to check the extent of the injury and club medics were left frustrated by the level of care offered by La Oranje - but the former Ajax playmaker himself is optimistic on his recovery.
"The injury was more serious than initially thought. Thankfully, at this stage there's no need for surgery, I'm now fully focused on my recovery."
Barcelona have not provided an expected return date for De Jong, but he's unlikely to be risked before September, and the defending Spanish champions will now activate their option to claim FIFA compensation.
FIFA's Club Protection Scheme regulations state clubs are entitled to compensation when a player is injured on international duty and is sidelined for more than 28 days. In De Jong 's case, he's expected to meet this threshold, with Barcelona eligible for a pay out.
The maximum compensation figure is €7.5M per player, but this amount is calculated using a daily compensation of up to €20,548, payable over a maximum period of 365 days.
The final total depends on the length of time De Jong remains out ahead of August ties with Elche, Athletic Club and Rayo Vallecano.