Real Madrid defender Antonio Rudiger is set to miss up to eight weeks after undergoing surgery on a knee injury on Tuesday.
Spanish and European champions Madrid also lost Ferland Mendy to a quadriceps injury, with the left-back likely out for at least two months.
Fellow defender David Alaba joined his teammates on the long-term injury list after it was announced by the club he had been "diagnosed with an internal meniscus tear in his left knee".
Rudiger was also banned on Tuesday for six matches after hurling an object at the referee during the Copa del Rey final defeat by Barcelona last weekend.
"Rudiger underwent surgery today (Tuesday) for a tear in the outer meniscus of his left knee," said Real Madrid in a statement, without specifying the expected length of his absence.
Spanish media reported Rudiger will miss between six and eight weeks during his recovery process.
Madrid have five LaLiga matches remaining. He will serve the final game of the ban at the start of next season.
The 32-year-old German centre-back may still be able to participate in Real Madrid's Club World Cup campaign this summer in the United States, with the tournament beginning June 14.
Rudiger was substituted in extra-time of Madrid's 3-2 defeat by their arch-rivals, and was sent off after his aggressive protests from the sideline.
Mendy was taken off hurt in the early stages of the final and he is set to miss the Club World Cup.
Madrid said Mendy was diagnosed Tuesday "with a rupture" in his right quadriceps.
The defender was brought straight back into the starting XI to face Barca for his first match in six weeks before hobbling off.
Madrid, second, trail LaLiga leaders Barcelona by four points, with the teams set to meet on May 11 at the Olympic Stadium.
With Dani Carvajal and Eder Militao also sidelined with long-term injuries, Madrid's defence is in poor shape for the run-in.