Sergio Ramos suffered knee ligament damage during Spain's 2-0 win over Albania on Monday, national team doctor Oscar Celada has confirmed.
The Real Madrid centre-back landed awkwardly after contesting a header and had to be substituted in the 80th minute of Sunday's World Cup qualifier in Shkoder.
Ramos has affected the ligament in his knee," Celada said. "We hope it's just be sprain in the lateral ligament, grade one or two."
Initial reports have suggested that Ramos faces at least a month on the sidelined, but Spain head coach Julen Lopetegui is optimistic that the injury is not too severe.
"We've had a very unfortunate international break in general. We've lost several players," he told a media conference.
"It seems to be a small sprain and so he'll be out for two or three games. We're optimistic that it's nothing very serious.
"We hope so, although the doctors still need to verify it."