The Red Devils head into the game having slumped to a 2-0 loss to the Reds at Anfield last week after a below-par display.
Rooney is currently sidelined with a knee injury and will be unable to help his team-mates at Old Trafford on Thursday night.
However, the England captain is confident that Louis van Gaal’s men have what it takes to overturn the 2-0 lead, despite conceding that it will be tough for his team-mates.
Speaking to the Daily Mirror, Rooney said: “I think Liverpool is going to be tough Thursday – but two goals is doable.
“We have good players and the first goal will be important. If we get that, then we will be back in the game.”
Rooney is hoping to be back in action in April as he bids to return from his knee injury as soon as possible.
United came from a goal down to earn a 1-1 draw with West Ham in the FA Cup quarter-finals on Sunday.
MORE: The latest football news