Real madrid didn't make much signings as Barcelona this season, Ancelotti did mention that he was satisfied with the players he had already and with few additions he was ready to kick start the season, those statements he made turned out to be right and proves he knows what he is doing. The current players in the team have shown satisfactory performances this season. Barcelona also have shown improvement this season afteraki g several signings this summer and before. As the season grows old we will see how well both teams have improved and who is the favourite to win the trophy.
He may be right, but what if Ancelotti loses some players through injury, do you think other players are ready to cover it well without any problems?
I imagine some of their midfielders like Modric or Kross are injured, it will definitely get Ancelotti in trouble because the substitutes are not as good as either of them.
Up to date, there doesn't seem to be any problem with Real Madrid's form. But I'm sure they will have difficult things if more of their main players get injured or accumulate cards so they have to miss a few match.