The Spaniard has called for consistency and believes the Blues are capable of beating the Red Devils in the FA Cup quarter-final replay at Stamford Bridge on Monday
The Blues go into the quarter-final replay at Stamford Bridge on Monday afternoon looking to bounce back from Saturday's 2-1 defeat to Southampton and secure a place in the semis where Manchester City await.
Despite the defeat to Mauricio Pochettino's men, however, Benitez is looking for his side to bounce back and is confident in their ability to mix it with the champions-elect.
"Monday is a big game against a very good side but we showed in Old Trafford we could do it, and we will try to," the Spaniard told the club’s official website.
"United are top of the table and we were better than them in the first game. We can compete. When you play two games in three days it is not easy, and we are doing well for the situation we have.
"United have a very strong squad. Analyse the four strikers they have, we have two. It was a problem when we had just Fernando Torres but with Demba Ba we have two options. We have offensive players with enough quality to create, but in some positions to find the balance is not easy.
"To play two games a week for four months is not easy to keep the team at the same level the whole time.
"We have played some nice football, scored a lot of goals, but still, we have to be more consistent."
Benitez is expected to recall Eden Hazard, David Luiz and Juan Mata after all three were absent from Saturday’s loss at St. Mary's, with the former Inter boss choosing to rotate his squad for the league fixture.
"The players that were training with us during the international break, I knew they were fine and ready," he continued. "The players coming back, you think, ‘okay fine’, but the team were good enough to beat Southampton if we played with the same intensity of the second half.
"When everything is going well and you have to make decisions, everybody is happy and more confident for the next game.
"We play at a level we played two weeks ago we can beat anyone. It's a question of everybody being focused and not making mistakes."