Real's website ran a picture on Sunday of their players celebrating a 2-0 semi-final first-leg victory at the Nou Camp in 2002 that paved the way for their ninth and most recent triumph in Europe's elite club competition.
Zinedine Zidane and Steve McManaman scored that night and the Spanish giants drew the return leg at the Bernabeu 1-1 before Real beat German side Bayer Leverkusen 2-1 in the final thanks to Zidane's stunning volley.
"Everyone agrees it will be difficult, but no one gives up hope," the club wrote.
"This historic precedent is just what Real Madrid need to have even greater faith in their chances on Tuesday."
Goalkeeper and captain Iker Casillas added his voice to the message of optimism.
"The names of the two teams that will play the final haven't been inscribed yet," the Spanish World Cup winner said.
"You never know what may happen. We will play in Barcelona knowing a final is set to take place in a month and that any of the four teams still in the championship may be in it."
The ill-tempered first leg in Madrid last week, when World Player of the Year Lionel Messi struck two late goals after Real defender Pepe had been sent off, resulted in UEFA opening probes into the two clubs.
They both filed a complaint about the other with European soccer's governing body, Barca reporting Real coach Jose Mourinho for belittling his counterpart Pep Guardiola's achievements and Real accusing the Barca players of play-acting.
COMMON SENSE
Barca president Sandro Rosell sought to ease tension ahead of Tuesday's clash, urging the club's fans to "show good manners and common sense."
"Our supporters are a model of good behaviour and I am asking them to show that again this Tuesday, especially because all eyes will be on us," he told the club's TV channel.
"I want them to support the team, forget about all the other stuff and not get provoked."
Barca and Real rested key players and were beaten in La Liga at the weekend, Barca surrendering the lead and losing 2-1 at Real Sociedad and Real going down 3-2 at home to relegation threatened Real Zaragoza.
The results preserved Barca's eight-point lead over Real at the top with four games left and the Catalans remain firmly on course for a third successive Spanish league title.
Barca's defence has been ravaged by injuries and their problems deepened on Saturday when they lost centre-back Gabriel Milito to a thigh strain and reserve team fullback Martin Montoya to a fractured clavicle.
There was more positive news on Andres Iniesta's calf injury when the Spain midfielder, who missed last week's first leg, took part in Sunday's training session.
HEROIC HABIT
Real will be without Pepe for Tuesday's game and defender Sergio Ramos is also suspended. Mourinho, who was sent from the bench for protesting Pepe's d
