Barcelona let a 2-0 lead slip to lose 3-2 to Real Sociedad on Saturday, and drew the first leg of the Copa del Rey clash with Malaga 2-2 at the Camp Nou.
“This past weekend we saw that Barcelona are not unbeatable and that it’s even possible to come back and win from 2-0 down against them,” Demichelis said.
“We have proved that we can cope with difficult situations or tough games. They may be angry and fired up and that means it could be harder to play them.
“Hopefully some seeds of doubt have been sown but they are a team used to going out and winning every two or three days.”