Real Madrid public relations director Emilio Butragueno believes Tuesday's meeting with Borussia Dortmund is one of the club's "biggest games in the last 10 years".
Four goals from Robert Lewandowski in last Wednesday's game in Dortmund have given los Merengues an extremely difficult task but, after seeing his team beat Atletico Madrid 2-1 on Saturday, Butragueno remains optimistic that they can overturn their 4-1 first-leg defeat.
"Tuesday's game is probably one of Madrid's biggest games in the last 10 years," the 49-year-old Spaniard told by AS.
"As the game gets closer, people's faith in a comeback will increase. Let's see how effective we are. These players can do it, for sure.
"Our fans are smart. They know when the team needs their support. They know the importance of the game, they understand the nature of the game and what we hope is that the team will deliver."
Butragueno, who won six Liga titles with los Blancos, also praised the team's Madrid derby victory, where the visitors recovered from a goal down to seal victory.
"The team has competed very well, even after conceding the first goal," the former Spain striker added.
"The defensive system has worked well and we have also taken advantage of our chances."
Real Madrid are second in La Liga with 74 points from 33 games and trail leaders Barcelona by 11 points.