Coach Pep Guardiola rested captain Carles Puyol, midfielder Xavi and high-scoring Samuel Eto'o on Saturday when Barcelona beat Recreativo Huelva, 2-0, in La Liga to have them ready for Tuesday's game at the Allianz Arena.
Guardiola is about the only person to give Bayern a chance.
"Bayern are capable of scoring four goals, all the more so when they are wounded," Guardiola said. "I don't believe the statements about them already having given the series up for lost. I am sure they will put in a good performance and we have to go there with a lot of ambition to win the match. If we are speculative, they will roll over us."
Guardiola will watch the game from the stands after being tossed by referee Howard Webb in the first leg.
Bayern's defense will feature three changes. Goalie Michael Rensing has been benched and replaced by 34-year-old keeper Hans Joerg Butt. Defenders Lucio and Philipp Lahm, who were sidelined with injuries and missed the first leg, should play.
Bayern Munich -- 22-Butt; 23-Oddo, 6-Demichelis, 3-Lucio, 21-Lahm; 8-Altintop, 31-Schweinsteiger, 17-van Bommel, 15-Ze Roberto, 7-Ribery; 9-Toni.
Barcelona -- 1-Valdes; 20-Daniel Alves, 3-Gerard, 5-Puyol, 16-Silvinho; 6-Xavi, 24-Toure, 8-Iniesta; 10-Messi, 9-Eto'o, 14-Henry.
Referee: Roberto Rosetti (Italy).