The Blues are currently 12 points behind in the title race, after having won just twice in their last seven games.
Ferguson said: “I would never dismiss Chelsea because the progress they have made in the last decade is there for everybody to see.
“They have won three titles, they won the FA Cup a few times. They are bang in there in the European competitions. They have reached semi-finals and a final.
“That experience will help them out of this bad spell.
“If you take the case of Arsenal, they were written off. Arsene Wenger was getting terrible criticism. Now everyone is saying they have a chance to win the league again. That is what football does.
“There is inconsistency from everyone at some point in the season. Everyone drops points. My aim is to make sure we don’t drop more than the rest.”
