Ancelotti demands reaction to Clasico defeat
Los Blancos were knocked off top spot in La Liga by Atletico Madrid after losing for the first time in 31 games in all competitions.
Atletico lead due to their better head-to-head record against Real, whilst Barca are now right back in the hunt to retain their title as they are just a point behind the two sides from the capital with nine games to go.
On paper, Real face the toughest task in midweek with all three sides in action on Wednesday as Barca and Atletico host Celta Vigo and Granada respectively.
And with that in mind, Ancelotti believes Real's reaction against a Sevilla side that have won their last five league games could hold the key to the title race.
"I have said to the players that in general they played well (against Barcelona). They played with intensity and fought until the end," he said.
"Now we need to forget this game and think about Wednesday, which could be the key game of the season.
"I have said many times that nothing will be decided until the last game of the season.
"We need to fight and react well. We have a very important game on Wednesday and we need an immediate reaction."
Real will be without the suspended Sergio Ramos and Angel di Maria, so Raphael Varane and Isco are expected to start.
Atletico took advantage of Real's defeat to move back to the top of the table with a comfortable 2-0 win over bottom-placed Real Betis earlier on Sunday.
Los Rojiblancos now have the destiny of the league title in their own hands, although they do face a potentially decisive trip to Barcelona on the final day of the season.
Atletico captain Gabi, though, believes his side can finish off an amazing campaign in style.
"We believe a lot in this group as a team and we are working every day to be amongst the best," he told the club's website.
"We have nine finals left ahead of us and if we want to be on top we need to win all of them."
Left-back Filipe Luis will miss the visit of Granada as he saw his fifth booking of the season against Betis. Emiliano Insua will deputise for the Brazilian, whilst David Villa, Diego Ribas and Jose Sosa could also come into the side with a difficult looking game away to Athletic Bilbao to come on Saturday.
Meanwhile, Lionel Messi will be targeting a third consecutive hat-trick as Barca welcome Celta to the Camp Nou looking to move top for at least a couple of hours as both Atletico and Real kick-off later on Wednesday.
The Argentine became the all-time leading scorer in El Clasico at the weekend as he moved onto 21 goals from 27 games against Madrid and also took his tally for the season to 34 in as many games.
Barca boss Gerardo Martino acknowledged that his side had to beat Real to remain in the title race and claimed that the league "has started over" for the three title contenders.
Martino is expected to rotate his squad against Celta with Pedro Rodriguez and Alexis Sanchez in contention to start.
Elsewhere, Athletic Bilbao will look to consolidate their place in the fourth Champions League place when they travel to Elche.
And it is also an important round of fixtures at the bottom as Rayo Vallecano host Osasuna, whilst Getafe, Almeria and Valladolid face tough games against European hopefuls Villarreal, Valencia and Real Sociedad respectively.
Fixtures (all times GMT)
Malaga v Espanyol (1900)
Elche v Athletic Bilbao (2100)
Rayo Vallecano v Osasuna (1900)
Barcelona v Celta Vigo (1900)
Sevilla v Real Madrid (2100)
Atletico Madrid v Granada (2100)
Getafe v Villarreal (1900)
Real Sociedad v Valladolid (1900)
Almeria v Valencia (2100)
Levante v Real Betis (2100)
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