The Reds had a lead but ended up losing 2-1 to Lyon on Tuesday.
Benitez told Sky Sports: “It will be more difficult. We have done it before, we won three games, so we have to do the same. We have to win three games.
“It is always important to think about the first game, to try and get the three points and then we will have more confidence.”
Liverpool skipper Steven Gerrard suffered a recurrence of a groin injury in the game against Lyon.
Benitez continued: “It is too early. We have two or three players with problems so we have to wait and see tomorrow with the doctor.
“He felt that he had a problem with his groin and it could have been more serious so we had to change him.”
Benitez added: “It was not a gamble to play Gerrard. He wanted to play and had trained normally for two days.
“He was given the all-clear by the doctor, and what happened was just bad luck. He felt something wrong in his groin, and it was wise to come off.”
