Eder Militao became the second Real Madrid player to suffer an anterior cruciate ligament (ACL) injury this week.
This was after goalkeeper Thibaut Courtois, and the LaLiga club said on Sunday that the defender would require surgery.
Militao was injured when he hyperextended his knee early in the second half of Real’s 2-0 win over Athletic Bilbao on Saturday in their La Liga opener.
The 25-year-old defender was in tears as he was helped off the pitch.
“After the tests carried out on our player Eder Militao, he has been diagnosed with a rupture of the anterior cruciate ligament in his left knee.
“The player will undergo surgery in the coming days,” the club said.
Militao could be sidelined for several months, just like Courtois who also required surgery after tearing the ACL in his left knee during a training session on Thursday.
Militao’s injury leaves only three fit centre backs for Real as the season gets underway – Nacho, Antonio Ruediger and David Alaba.