United were thumped 4-1 by Liverpool at home last March and still went on to win the championship but the stakes are higher than ever now.
The leaders are just two points clear of Chelsea, who have a game in hand and no Champions League to distract them after being dumped out by Inter Milan, and Arsenal as the season enters the final stages.
Liverpool are out of the title picture but Rafa Benitez's side are making an all-out push for fourth and a possible Champions League place and need every point they can get.
"It would be very dangerous to think this is a poor Liverpool side coming to Old Trafford because they will be anything but," midfielder Darren Fletcher told the Manchester Evening News.
"It would be a huge mistake to think that Liverpool aren't a threat. They maybe haven't had the season we expected after the one they had last year but they are still a dangerous side.
"They are still the same team they were last year in the main," added the Scot.
"We know what they are capable of because they pushed us all the way and dished out that defeat here and the one at Anfield this season. They are still fresh in our memories.
"We have to learn the lessons from last year's game. The warnings are there. If you are not 100 percent focused and you make mistakes then Liverpool will punish you."
He scored twice against Fulham at Old Trafford last Sunday to take his season's tally to 32 and is on course to surpass the 42 scored by Cristiano Ronaldo in 2007/2008.
While Rooney will be one of the leading lights at the World Cup in South Africa this summer, so too will Liverpool's Spanish striker Fernando Torres who also grabbed a brace against Portsmouth.
