Italy have won six of their eight Group G matches, but just one point from two fixtures with Spain has left the Azzurri in second position in the group, and facing a playoff in order to qualify for the 2018 World Cup.
Giampiero Ventura's side faced boos from their own supporters during the clash with Israel, and Verratti has claimed that "Italy fans are always pessimistic".
"I don't agree with the jeers, nor the criticism. It's never easy at international level, just look at France drawing with Luxembourg or Sweden beaten by Belarus," Verratti told Rai Sport.
"Italy fans are always pessimistic, but we know that things change quickly here and all it takes is one good performance to be considered a phenomenon, one bad game to be called unworthy of the shirt.
"We have won all our games in qualifying apart from against Spain, we must admit that at this point in time they are superior to us. We dominated Israel in terms of possession, with shots on goal and should've won by a bigger margin, so we need to be more efficient."
Italy will continue their qualification campaign at home to Macedonia next month.