The manager's side was officially eliminated from the La Liga title race Sunday, which he feels came down to its own lack of focus.
Carlo Ancelotti feels Real Madrid paid the price for failing to match its European intensity, after its Liga title bid was ended.
Back-to-back draws against Valencia and Real Valladolid preceded Sunday's trip to Celta Vigo, meaning that its hopes of challenging for the championship had all but ended prior to this weekend.
As it is, it must now watch from the sidelines as Barcelona meets Atletico Madrid in what will effectively be a title decider - after a double from Charles gave Celta a 2-0 victory to confirm Real's fate.
That proved particularly frustrating for Ancelotti given the trio of decisive slip-ups came after Real's 4-0 UEFA Champions League semifinal triumph at Bayern Munich, which sealed a 5-0 aggregate success.
The club is still on course for a historic Decima in Europe, but the Italian conceded it had failed to match those standards domestically in recent weeks.
"It is true that in the last three games we have not done well," Ancelotti said. "From the semifinals, we have lowered the intensity and paid dearly."
For Real, all eyes now turn to Lisbon, where it will tackle city rivals Atletico in the final of Europe's premier competition May 24.
"We now need to look at what we have done well to recover energy and recover the players for the final," Ancelotti added.
There is, though, plenty of cause for concern ahead of that point, with Cristiano Ronaldo missing out against Celta altogether because of a thigh strain, while Gareth Bale settled for a place on the bench having not been deemed 100 percent fit.
Ancelotti said: "Bale was not 100 percent, and I did not want to risk Cristiano. He had treatment this morning and is almost recovered; I think in the end he will play the next match against Espanyol."