According to SPORT, citing journalist Raul Salmurri, the midfielder has not suffered a ruptured anterior cruciate ligament (ACL), eliminating fears that he could have faced an extended spell on the sidelines.
While the Dutch international is still dealing with a significant injury, the latest findings mean he is no longer expected to miss as much as six months.
Instead, De Jong is currently projected to be out for around four months, although the final timeframe will depend on the treatment route selected.
Barcelona and the player are expected to decide together whether surgery or a conservative rehabilitation programme offers the best path to recovery.
The club had intended to fully evaluate De Jong once his World Cup commitments ended after he featured throughout parts of the tournament despite ongoing physical discomfort.
Despite the setback, Barcelona are not expected to alter their transfer strategy. Sporting director Deco is reportedly continuing with his existing plans, while midfielder Marc Casado remains available for a potential off-season departure rather than being retained because of De Jong's absence.
Should the Netherlands star remain unavailable into the new campaign, head coach Hansi Flick could instead turn to one of the club's emerging prospects.
The German has been closely assessing youngster Brian Farinas during first-team training as he evaluates whether the academy graduate is prepared to make the step up.
Barcelona's World Cup campaign has otherwise been highly successful, with as many as eight club players helping Spain reach the final, where they will face Argentina.
