Barcelona's Marc Casado has been ruled out for two months and team-mate Inigo Martinez also faces a spell on the sidelines after both sustained knee injuries in Sunday's win at Atletico Madrid.
The pair have been ruled out of Spain's two-legged Nations League play-off later this week against the Netherlands.
Midfielder Casado was forced off in the second half at the Metropolitano Stadium, while defender Inigo Martinez also picked up an injury in Barca's 4-2 win.
Barca said in a statement on X: "Additional tests were performed on first-team player Marc Casado, confirming a partial tear of the lateral collateral ligament in his right knee.
"He will undergo conservative treatment and is expected to be out for approximately two months."
The La Liga leaders added on their official website: "Tests on the same day also confirmed that Inigo Martinez has a swollen right knee. The player will undergo treatment in Barcelona under the supervision of the club's medical staff.
"The two players had been due to join up with the Spain squad for the upcoming international matches, but their physical problems mean that neither will be going on international duty."
