Xabi Alonso’s side suffered their first defeat of the season with a 5-2 La Liga defeat to local rivals Atletico Madrid on Saturday (September 27).
Atletico forward Julian Alvarez was particularly impressive, scoring a brace as Real Madrid fall down to second, one point behind Barcelona.
Speaking ahead of their Champions League clash with Kairat Almaty on Tuesday, Valverde admitted the defeat to Atletico forced them to do some reflecting.
"They were two very tough days, very upset by the defeat," he told reporters on Monday.
"We talked a lot; since I've been at Madrid, that's rarely happened, so many conversations. We have to change as quickly as possible. We emphasized the attitude on the pitch.
“Also with the coach, there were many conversations. We have to change as quickly as possible. We emphasized the attitude on the pitch. Also with the coach, there were many conversations. (On Tuesday), the first game, to change all that."