Atletico were trounced 4-0 by the European champions at the Allianz Arena, representing the joint-heaviest defeat the club have suffered since Simeone took charge nine years ago.
The Rojiblancos have not tasted defeat in La Liga this season and avoiding defeat to Manuel Pellegrini’s men to will extend their unbeaten run in the Spanish top flight to a club record 21 games.
"I absolutely trust the team, despite the painful, heavy defeat in Munich," Simeone told a news conference on Friday.
"I got a lot of positive things from the game and I totally believe in the team we have.
"I see them play with great enthusiasm, with great intensity and eager to be the protagonists.
"Tomorrow we will see it [the team's personality]. I absolutely believe in my players, I know their quality. We face a team that with Manuel have improved a lot, especially their enthusiasm, defence, and the confidence you can see in Betis beyond the results.
"They won twice away from home, so they are a dangerous team. Maybe, if I am not wrong, they are one of the teams who have created the most chances in LaLiga."