Munoz completed £34.5M move to Anfield earlier this month, after the Reds activated his release clause at Osasuna, and he will join up with his new teammates for preseason training next month.
Reds fans hoping to catch a glimpse of the 22-year-old in North America has been placed on alert after the Spanish FA (RFEF) confirmed a fresh injury setback for him in recent days.
However, La Roja head coach De la Fuente offered a more positive update on the Catalan's recovery, but admitted the distraction of a move to England has impacted him.
"Victor will be very important for us at this World Cup. He had a small injury problem, but it wasn't a relapse. He's also experienced a lot of emotions in the last few weeks.
"There's been lots of tension (Osasuna's relegation battle, injuries, moving to Liverpool) and that may have stressed him out. Now he needs calm but he will be very important for us."
Munoz has been an unused substitute in both of Spain's Group H games so far after a 0-0 draw with Cape Verde and a resounding 4-0 win against Saudi Arabia.
Spain wrap up their group stage campaign against Uruguay on June 26th in the Mexican city of Zapopan.