The Senegal international has been a revelation on Merseyside since joining for around £30 million from Southampton in the summer, scoring three and laying on another in six Premier League appearances.
His impact comes just a year after Manchester United came in for him, in the summer of 2015, although then he turned down their advances to stay at St Mary's.
And having already established himself as a key player in Jürgen Klopp's side, he is relishing the opportunity to go head-to-head with United as the Reds look for a sixth straight win in all competitions.
Mane: Liverpool players believe we will beat United
Speaking to the Telegraph, Mane said: "We are going to beat Manchester United. We all believe it. We are going to make it.
The 24-year-old admitted that is might be "the biggest time I have played in" and said that "everyone would like to score in a game like this."
Mane also gushed with praise for his new manager, insisting that "everyone likes Klopp" and calling him "one of the best in the world."
He added that to work with his as a coach makes "us [the Liverpool squad] all happy" because he "knows how to motivate players, engage with them and give you more confidence."
The winger continued: "He tells us all to always be hungry to win and become one of the best. Whenever I play, I know I have the support to help me."
I didn't need a second minute to think about signing for Liverpool, says winger
Mane was also quizzed about nearly signing for United a year ago, insisting that it was his decision to remain on the South Coast and continue his development with the Saints.
He added that then-Southampton boss Ronald Koeman, now managing at Everton, was "not happy with all the rumours" because he wanted Mane to stay, but the forward said: "It was not too complicated because for me it was not time to go."
Mane explained that in a personal conversation with Koeman, he told him he would stay and said it was his decision because he "wanted to stay at Southampton."
"I was patient because I remember after the first year I knew it was better to focus on Southampton," he continued, saying that he needed to "be there a couple more years and prove something."
He said that he was "convinced" that he "still had to prove something" there, as well as wanting to "improve more and learn more" before moving "to a bigger club."
But he added that he "knew when the right time" to leave was, when Liverpool came in for him just a few months ago.
Mane felt that the extra year with Southampton "helped me get better" and said it is "important for every player to go step-by-step."
"It was only when Liverpool came in that I never had a second thought and knew I wanted to join," he declared, calling it "different" because it was "the right moment" to move on.
He said: "I finally came to Liverpool and I was happy with that, and now I'm happy I am playing against Manchester United."