The two most successful clubs in English football history will lock horns with United joint-top of the table and seven points better off than their arch-rivals.
There have been many discussions lately regarding how Liverpool manager Jurgen Klopp has fared at Anfield, seeing as he's now been at the club for two years.
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After the two teams' respective transfer business in the summer, some fans are starting to believe that a gap is opening up between Man Utd and Liverpool.
However, Klopp remains steadfast in his beliefs and has now claimed that he will walk away from his role as Liverpool boss once one key thing has happened.
Klopp on what it'll take for him to leave Liverpool
Despite an indifferent start to the 2017-18 campaign, Klopp doesn't feel that Liverpool have been left behind by the likes of Man Utd, Manchester City and champions Chelsea.
In fact, the former Borussia Dortmund manager has insisted that he'll leave his current side the moment he thinks that they can no longer compete with the biggest clubs in the league.
"In the moment when I think we cannot be successful, and there is only consolation, I go," the 50-year-old German told reporters, via Goal.
"Why should I be here as some kind of caretaker until the world creates a manager who can be more successful? That makes no sense. I am really convinced.
"Other managers have different ways to do it. Other clubs have different ways to do it. We have our way. I don't think I'm the perfect manager. I only think I'm the perfect fit for this club and I feel already much more responsible than maybe I should."
Klopp continued: "If your neighbour has a better situation, he's got one more car, he gets to go on one extra holiday, does it mean you can't enjoy your own situation?
"It's about us being happy, not others. Can we dominate them for the next 20 years without spending the same amount of money? Probably not."
The Reds boss added: "But can we still be there? Yes, of course. And we want to force this. We want to be consistent, constant at our high level and improve it.
"Even when we lose a player in the future we want to bring in other players. That's the benefit of a long-term project."
Klopp's Liverpool can provide a clear sign of their competitiveness by achieving a positive result against Man Utd before their Champions League tie at Maribor on Tuesday.
Do YOU think Klopp is under pressure at Liverpool? What do YOU think must happen for him to consider his position? Have YOUR say in the comments box below!