The 30-year-old made glaring mistakes against the likes of Hearts, Arsenal and Norwich but the Reds boss is not concerned.
"I can't speak highly enough of Pepe. He's a keeper who has really impressed me," he said.
"Pepe has been here for a number of years and has proved himself over a long period of time.
"Like all the other players here he's trying to improve and become a better player. He's obviously adapting to a new style but this is a way of working which is perfect for Pepe.
"He came through the Barcelona model so he understands this way of playing and what I'm trying to do perfectly. As a team, we just need to cut out the kind of mistakes 'we've been making. If we do that then everyone will benefit from that, including Pepe."