Pep Guardiola, the Barcelona coach, promised his side will not compromise their footballing principles because they will lose if they attempt to take on Chelsea in a physical fight.
Barcelona were critical of Chelsea's no-nonsense defending in the goalless draw in the Nou Camp last week, and Guardiola will tell his side to stick to their gameplan, no matter how tetchy the semi-final second leg becomes.
Guardiola said: "If we try to combat Chelsea physically, that will play into Chelsea's hands. We want to play our football around Chelsea. We don't want to get into physical battles with them, because that's their strength. If we go through, it will be on our own merit. I only know one style of playing. I only know that we should attack and try to score a goal.
"The team that gets through is the team that deserves it and really wants it," he added. "It won't be down to refereeing decisions or anything.
"I go into this game telling my team that Chelsea are going to play the game of their lives."
Thierry Henry is a late worry with a knee injury, and if he cannot play Andres Iniesta would be pressed into attack, with Seydou Keita coming into midfield.
Guardiola also has to decide how to patch up his defence without the injured Rafael Marquez and the suspended Carles Puyol. The likely option is to put Eric Abidal in the middle, and a recall for 35-year-old former Arsenal defender Sylvinho.