The Spanish team has confirmed that Sergio Busquets has a slight ligament sprain in his left knee.
More will be known after the midfielder undergoes an MRI on Monday.
The Barcelona man was substituted in the 72nd minute when Spain drew with Switzerland on Saturday night.
The RFEF also confirmed that he is missing Sunday’s training.
Busquets has started all seven of Barcelona’s league games so far this season. Although Frenkie de Jong is being given greater responsibility in midfield, Ronald Koeman will be eager to have the Spanish midfielder available again as soon as possible.