"For me, Neuer is the best goalkeeper in the world at the moment. Casillas is past his best, whereas Neuer is still getting better," Taffarel told Bild.
"The way he plays as a goalkeeper and his technique are extraordinary. Not just in possession, but mainly how he parries and catches shots. Someone like Oliver Kahn never had this kind of technique.
"Kahn was a great goalkeeper, but Germany have had better shot-stoppers. Neuer is definitely better than Kahn was. I've known for years that he would become an impressive goalkeeper."
Casillas has spent the early part of the season out of the Real Madrid team.