To be honest, Real Madrid was really unlucky during this season because they lost many players and got injured a lot, but they still had good performances. However, they have good enough players to fill the places of these players in the team. Recently, they lost Éder Militão, their Brazilian dancer, which can have a negative effect on this team because this player had a key role in Real Madrid.
In the game against Osasuna, Éder Militão got injured hard which even made Vini Jr very unhappy because he saw Militão's injury as hard enough.
It seems Militão is going to be out for nine months.

Militao previously has been gets ACL injured on his left knee and he have to rested for long time and after fully recover Militao this season can performing well so far he was played 12 times during this season so this proven he is very important for Real Madrid but unfortunately Militao has gets more ACL injured again but this time on his right knee which this is very bad for his career because the players who already gets ACL injured usually will be hard to bounce back and indeed it is confirmed that his injured has 9 months duration which mean Militao have to ended this season early and for Real Madrid this is very bad because majority of their defender players are got the injured and this january i think Real Madrid have to bought the players
Real Madrid's victory had to be paid dearly due to Militao's injury, and this has increased the number of Real Madrid players who have been injured, especially players who play as defenders. With Militao's injury, I think Militao's career will end because as you said he previously had an ACL injury in his left leg now in his right leg, in theory it is difficult to return to his best performance, let alone eliminate the trauma.
From this news, Real Madrid this season seems like it will be difficult to compete, too many are injured. Unless Ancelotti can accept and give opportunities to players who are La Fabrica products, but Ancelotti is a typical coach who does not want to take risks, for example by playing young players who are inexperienced, especially La Fabrica products. Endrick and Guller alone only got a few opportunities with Ancelotti. The only way is for Ancelotti to buy a defender in the transfer market later so that he can compete in La Liga and the Champions League. This is the impact of the new UCL format which will ultimately harm many teams due to injuries caused by a tight schedule.