"United is a difficult place to go because they are a strong team with good players," said the skipper.
"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 race so 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 so we know if we play to our maximum potential then we can cause an upset.
"We have proved against these teams that on our day we can beat them. That was the important thing. Where we have gone wrong at times this season has been at home in games when we should have been beating teams comfortably when they have come to play defensively. We need to learn to get maximum points even when we're not playing to our potential.
"We've experienced the disappointments this season of drawing games we should have won but the important thing now is to just think about the games coming up. We have to stay positive and just try and win all the games we have remaining."