He added in an interview with TVE: "We're not going through a good moment, that's clear, but we also struggled at the start of past year and ended up winning a third successive Champions League, which is something historic". Once they play with this seriousness, commitment and wanting to score.
Madrid again started the game less than fully focused, which was a feature of the ill-fated start to the season under previous coach Julen Lopetegui.
In temporary coach Santiago Solari's first Champions League game in charge Real began slowly but were out of sight before halftime after a clinical masterclass of finishing.
FW Karim Benzema, 8 - The often maligned Frenchman's opener tonight was highest quality, driving into the box and then dummying three Plzen players before expertly finishing for his 200th goal for Madrid. All matches are different, you have to continue working with humility, sacrifice and ambition for your objectives and think about the next game. "A 5-0 win in the Champions League - I can only be happy with that".
Live stream: You can watch the match live via FuboTV.
"It was an important night for us", Casemiro said.
One of the big calls Solari has made since taking over was to end a policy of rotating goalkeepers between La Liga and the Champions League, with Thibaut Courtois now starting both competitions and last year's first choice Keylor Navas now thought to be unhappy at being benched.
Plzen, the reigning Czech champions, had two attempts on goal from long range in the second half, but Jan Kopic saw his effort stopped by Courtois and Patrik Hrosovsky, who scored for Plzen in their 2-1 loss in Madrid in October, fired wide.
"He is a great coach, we now have more confidence and we are going to compete".