The Spain legend has expressed his disappointment with his former side's present plight, claiming attitude and 'a lack of luck' are the main reasons behind their poor form
The reigning Liga champions were undone by Piotr Trochowski's second-minute strike, a result which leaves Los Blancos eight points behind arch-rivals Barcelona.
"There is a big deficit with Barcelona, but we must continue. On Tuesday we have an important match," the club's 49-year-old former vice-president and current director of institutional relations told Canal+.
"We lacked the luck to get back into the game, and there was an attitude problem. We must be united, whether we are winning or losing."
The Spaniard went on to comment on Cristiano Ronaldo's much-publicised unhappiness at the club, but refused to be drawn into a discussion on whether financial motives are behind his apparent discomfort.
"He is a key player, hopefully he'll continue for many more years here," Butragueno added.
"[We already spoke about money], we need to return to normal."
Madrid begin their Champions League campaign on Tuesday, when they welcome Premier League champions Manchester City to the Santiago Bernabeu.