Liverpool are seven points behind United and the Red Devils also have a game in hand.
“United is a difficult place to go because they are a strong team with good players,” Gerrard told the club’s official website.
“This time around the game is bigger than it has been for a few years. If we can take maximum points off them then it will give us a better hope of getting back in the [title] race. There is everything to play for.
“We have to be confident. What’s the point going into a game thinking you are only going to get a draw or a defeat? It’s important we are positive.
“We have beaten them at Anfield this season and, although it’s at their place this weekend, it’s still a football pitch. We know if we play to our maximum potential then we can cause an upset.”
He added: “There’s still enough time for us because there are quite a few games left to play.
“While it’s still possible myself and the players will continue to fight, there’s no two ways about it. We won’t give up until we can’t do it.
“Manchester United have still got some tricky games, including against us. If we were to win every game and United don’t slip up, then obviously there’s nothing else we can do.
“We just have to make sure we stay on their tails and try to make the gap smaller. If they do make any mistakes, that’s when we have to try to pounce.”