The SPL champions pulled off one of the greatest upsets in recent Champions League history with victory over the Catalan giants but the Spanish midfielder believes that his side need to move on from their surprise defeat.
Xavi told reporters: "You have to be top of the group. We missed the opportunity to do that [against Celtic], but we depend on ourselves.
"We have to go and seek victory in the two remaining games."
Barcelona are two points ahead of Celtic in Group G with two matches remaining.