Real Madrid seeking first LaLiga win in Kylian Mbappe's home debut
Ancelotti was left fuming after last weekend's start to the season - a lacklustre 1-1 draw at Mallorca - telling reporters: "We had to do better, show more attitude."
Mbappe and most of Real's so-called "New Galacticos" put on a dreary performance at Mallorca, with goalkeeper Thibaut Courtois working his magic a couple of times to salvage a point.
"It was a game we could have lost because we didn't have balance," Ancelotti said. "It wasn't a good game. We are a very attacking team and defensive balance is a fundamental part of the way we are built."
At Mallorca, and in their UEFA Super Cup 2-0 win against Atalanta last week, the Italian manager started Mbappe in a central role as a forward just in front of a three-man line formed by wingers Vinicius Jr and Rodrygo either side of Jude Bellingham, with only two pure midfielders in Fede Valverde and Aurelien Tchouameni.
With the departure of German midfielder Toni Kroos, who retired after a remarkable decade with the Spanish giants, Ancelotti decided he was better off giving up stability in the centre of the pitch to gain more ammunition in attack.
However, against Mallorca and in a large part of the Atalanta clash, Mbappe was not the factor he was expected to be and Real were vulnerable to counter-attacks, suggesting they may need to work harder than anticipated to fit their blockbuster signing into the squad.
"We struggled to steal or press after losing the ball," Ancelotti said. "Defending is a collective commitment. The balance is found with the players thinking about the same thing. It is a problem of a team that did not understand that this was a key aspect of the match."
Under the shiny new roof that will shield a sold-out crowd from the relentless sun on a scorching summer afternoon in Madrid, Real face a newly-promoted Valladolid who are fired up after kicking off their campaign with a deserved win against Espanyol.
Hansi Flick's Barcelona also began the season well, with a Robert Lewandowski double allowing them to fight back to win 2-1 at Valencia despite them missing several key players and featuring three 17-year-olds from the start of last Saturday's game.
Coach Flick will still be unable to count on new signing Dani Olmo, who has yet to be registered with LaLiga due to Barca's breach of Financial Fair Play (FFP) rules, for Saturday's match against last year's Copa del Rey champions Athletic Bilbao.
Barca are running against the clock to try to negotiate the sale of players such as Vitor Roque, Ilkay Gundogan or Clement Lenglet so they can profit on the balance sheet and be allowed to register the versatile attacking midfielder who stood out in Euro 2024, helping Spain to win the title.
In Madrid on Sunday, Atletico will host last year's surprise package Girona after both sides were held to draws in disappointing openings last weekend. Manager Diego Simeone will have at his disposal new signings Julian Alvarez and Conor Gallagher.