The Reds have slipped six points adrift of their opponents and current league leaders following a run of five top-flight matches without a win, and four in a row without a goal.
Thursday's 1-0 home defeat at the hands of Burnley means that Liverpool's only win and only goals so far in 2021 came in their FA Cup third-round win over Aston Villa's youngsters, and Sunday promises to be another difficult test against an in-form Man United side.
Here, Sports Mole looks at how Jurgen Klopp could line his side up for the contest.
Liverpool could again be without captain Jordan Henderson for this match after he missed the defeat to Burnley with a slight muscle strain.
Klopp has insisted that it is not a serious injury, but the quick turnaround between fixtures, coupled with the fact that Henderson did not even make the squad against the Clarets, suggests that he will not recover in time for Sunday's heavyweight showdown.
Henderson joins Diogo Jota, Naby Keita, Virgil van Dijk and Joe Gomez in the treatment room, but there was better news on the injury front in midweek with Joel Matip returning at centre-back and Kostas Tsimikas being included among the subs.
Tsimikas could be in line to start, though, with opportunities to rest Andrew Robertson having been few and far between so far this season. Tsimikas is unlikely to play the full 90 minutes having only just returned from injury, but he may get some minutes under his belt from the start on Sunday.
Other fringe players such as Neco Williams, James Milner, Curtis Jones and Takumi Minamino could also come into the side as Klopp looks to freshen things up following a spell in which his side have looked short of ideas.
Thiago Alcantara, who ran the show for the opening half an hour in the league meeting between these two sides a week ago, may start again in midfield after missing so much football during the first half of the season.