The Argentine is set to start against the La Liga giants, with Claudio Bravo suspended after his red card in the game at the Camp Nou a fortnight ago.
And Guardiola says he has total faith in Caballero, a player he says has impressed him so far this season.
“He’s helped me very much from the very first few games,” Guardiola said. “I like him on a personal level.
“Every time he’s played, he’s played well. He gives me a lot of confidence.
“If he plays well we’re happy, if he doesn’t we will try and help him. I’m very happy with him, we have no doubts about him.”
It was a feeling backed up by Nolito, a player who turned down a move to Barcelona this summer in order to join Guardiola’s City revolution.
He described Caballero as “a great ‘keeper,” and opened up about the impact he has in the dressing room.
“I think tomorrow, obviously, Claudio Bravo doesn’t play because he was sent off - but we have another great goalkeeper in Willy. We have two great goalkeepers.
“Willy is normal person. Just knowing him from the short time I’ve been here, he’s great guy, a good character, he speaks Spanish as well.
“Hopefully he will play very well tomorrow.”
