Among the players mentioned in this list, 6 players are very important players for Madrid's squad. And these are the players we see in Madrid's starting XI. With half of the players in the starting XI facing injuries, Madrid's performance will naturally be somewhat unstable. There is no doubt that Ancelotti is an experienced coach. But since so many important players of the squad are not with the squad, we don't know how Madrid will perform in the next three matches.
I think it's 4 players that are very important to the starting 11 from the injury list. Bellingham, Camavinga, Tchouameni and Militao. Madrid can play well without the rest. Alaba is a good player but is very injury prone and Madrid has been playing fine without him for a while now. Same with Mendy, but I think they'll have to go to the B team to get a replacement or Lucas Vasquez will play his position. These are players that Madrid will really miss, just as they have been missing Bellingham already. Hopefully, the injuries are not that long and they come back before they lose too many points.
Madrid will play against Real Sociedad, Stuttgart and Espanyol in their next three matches. Madrid needed the likes of Bellingham, Tchouameni and Camavinga in matches against Sociedad and Stuttgart. Without these three key midfielders it will be difficult to keep the squad stable and win these two matches.
The most difficult games for Madrid in my opinion will be the La liga games. The champions league games seem to be something they know how to deal with because teams from other countries don't really know how to play Madrid, but La liga teams have understood them and will give them more difficulty.
Real Sociedad is going to be a difficult game because aside from the injuries, more Madrid players were on international duties than Sociedad players so that gives them a little advantage too.