Unai Emery was disappointed with his Sevilla side, whilst Aitor Karanka thought the resounding win was ideal preparation for the Champions League.
A Cristiano Ronaldo hat-trick and an early Karim Benzema strike were enough to give Los Blancos the three points.
But the 41-year-old has claimed that his men made it too easy for Jose Mourinho's team.
“At the end of the day, you have to look at what they've done and what we have not done,” he told a Press conference.
“We made things far too easy for Madrid. For the first 25 minutes I didn't recognize my team.
“We worked well in training throughout the week, but then we hid here tonight.
“The key is to work harder. Today was a bad day for us.”
The 39-year-old meanwhile has claimed that there is no better to way to prepare for the game with the current Premier League leaders.
“We are going into the Manchester United match in good form,” he told a Press conference. “And not just because of this result.
“Apart from the match against Granada, we have been showing good things throughout January.
“We played well this evening and gave a bit of a rest to key players. Sevilla have quality players, and although we were 2-0 at half-time, they could have caused us some trouble.
“But we scored the third goal right at the start of the second half, and that calmed everyone down.”
He also praised Cristiano Ronaldo, who having scored a hat-trick, received a standing ovation from the crowd as he came off midway through the second half.
“Cristiano has always had that admiration and he knows how important he is for the team, It is important for us that a player like him is at that sort of level.”