I think, all the Real Madrid players are doing greatly well in this season and even the new players they signed into the team this season are doing well also, which is a good confidence for Real Madrid head coach to make a good decision in this season. Real Madrid have strong players their head coach can use to replace any players that have injuries and they will still do what will bring victory to them at the end of the match, because they have good players that can represent the team in any competition. I don't think, Real Madrid will miss their opportunity in their next match, because the team they are going to play cannot stop Real Madrid not to embrace victory from the match.
Madrid is one of the big teams of La Liga who has always been the strongest candidate in the UCL competition and that is the reason why management and coaches always maintain the quality of squad performance. As you say if Madrid always has a talented player and all of Ancelotti is careful in choosing a player who really has a big talent quality and is able to help Madrid appear better. The injured player is always a big problem, but for Madrid it is not a big problem because all the players owned by Madrid are always ready to replace the position of injured players and have a good contribution.
And related to the El Clasico match, I think Madrid will still win the match. Vinic and other key players are always ready to beat Barcelona.