United have failed to keep pace with the leaders this season but Zabaleta expects the derby to have lost none of its edge and is anticipating a difficult night at Old Trafford.
The Argentina international, 29, said: "It doesn't matter, the situation of United. The game is special for both teams.
"We know how important it is to win the game for the players, the fans, the club. That is why we need to go there and try to win the game.
"We know Chelsea at the moment are on the top and even if we have got three games in hand we need to win there and see what happens next game.
"We have won at Old Trafford recently and hopefully we can do it again - but it is not just the United game. We need to win all of them."