Real lost Sunday's El Clasico to Barcelona, twice throwing away the lead to go down 4-3 in front of their home fans.
The result had serious ramifications for the title race, with Barca clawing to within one point of leaders Atletico Madrid and Real with nine matches of the season remaining.
And while the defeat has clearly hurt Real - Cristiano Ronaldo and Sergio Ramos both publicly slammed the officiating of referee Alberto Undiano, who awarded three penalties, two of which went to Barca - Ancelotti has urged his players to move on quickly.
"We have to forget this match and think about Wednesday, which could be a key game in the season," the Italian said.
"We have to be happy with the way we played (against Barcelona)…luck was not on our side but the team proved to be fit and we have the drive and ability to put this match quickly behind us.
"La Liga is wide open and we are going to keep fighting. There are nine matches left and, as I have said, it will be a very intense race for everyone."
Karim Benzema scored twice against Barca before being sacrificed after Ramos was sent off - for the 19th time in his Real career - and is expected to lead the line again.
Angel Di Maria was also outstanding for Real, but they did not get enough from stars Cristiano Ronaldo and Gareth Bale on club football's biggest occasion and Ancelotti will want the pair to reprise their performances from the reverse fixture back in October.
Ronaldo scored a hat-trick and Bale added two in Real's 7-3 home demolition of Sevilla. Ramos will be suspended for the visit of his former club after his latest red card and Jese Rodriguez (knee) is sidelined for the foreseeable future.
Sevilla will be quietly confident of pulling off an upset after a week that has included two important wins.
After knocking rivals Real Betis out of the UEFA Europa League's last 16 on penalties, the fifth-placed outfit won 2-1 at Osasuna on Sunday.
Unai Emery's men have won their last five La Liga fixtures - a run that has seen France forward Kevin Gameiro score four times.
Carlos Bacca and Ivan Rakitic have also impressed in recent times and Sevilla's form means Real must take their challenge seriously.
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