The Premier League is, of course, where the real action is, with both clubs wanting three points for different reasons—United want to make the most of Manchester City's decidedly unimpressive start, while Liverpool are searching for their first win of the season.
These two huge clubs are massive rivals, of course; both on a north-west England and a global scale, with fanbases running into the millions.
They haven't been head-to-head at the top of the league table since 2009—but the rivalry is burning just as strongly as ever. Here are five reasons why.
It's been a long wait for Liverpool supporters to see their team lift the championship trophy again, but in the meantime Manchester United have made full use of their superiority, dominating the landscape of English football for two decades and now racking up 19 league titles to the Reds' 18.
In terms of European success though, Liverpool remain the superior; three UEFA/Europa League Cups and five European Cups/Champions Leagues mean that they are still top dog in that regard.
Domestic cup success has been varied and relatively consistent for both teams over the Premier League era too.
Every trophy won is a point scored in the race and the rivalry between these two sides and they take great pleasure in reminding their opponents of any successes at all, both in the recent and the not so recent past.
It burns Liverpool supporters, deep and painfully, to know how far they are from the very top of the English game right now.
Having spent a decade floundering in the middle of the top half it looked as though they were on the verge of challenging once again when, in 2008-09 season they ended the campaign second, forcing United every step of the way.
A year later and the club was in freefall, on and off the pitch.
The decline has been stopped since then, but it is still going to be a long and arduous road back for the Merseyside club and United show no signs of slowing their steady march towards another title challenge in the mean time.
The two managers of last season, Alex Ferguson and Kenny Dalglish, were battle-opponents of old and while they might have had respect for each other, they certainly shared very little warmth.
Comments and questions lightly jibing the other were a common feature, as was the case when Rafa Benitez was in charge of the Reds.
Now Brendan Rodgers is in the Anfield hotseat and his relationship with the United manager is yet to be established.
It is likely to be a respectful, cordial one to begin with—but ultimately the need to defeat United for Liverpool, and vice versa, and the inevitable injustice that one man or the other will feel in defeat somewhere along the way will see the relationship become one of rivalry just as much as that of the two sets of fans is.
The less said about one particular incident which now needs to be moved on from, the better—but aside that, there is always a clash or two on the pitch.
Whether it was Steven Gerrard's red card in the FA Cup fixture in 2011, Rafael's ridiculous antics last season or just general thundering challenges coming in from either set of players, there has always been a fiery atmosphere and the absolute necessity of victory ensures all 22 players who start give everything.
Every tackle, every shot, every foul or near-miss on goal brings about a roar from the stands and the players themselves have to tread a fine line between increased determination of playing in the "big game" and keeping their mind focussed on picking up the three points.
Probably the most important individual factor of the upcoming game will be those in the stands; the fans.
Rivalry and even an intense dislike of an opponent's team is fine, necessary even at the highest level of the game, but there is a line which is crossed too often.
Unsavoury, degrading and just plain ignorant chanting and songs have no place in the game and should not be the focus of the match.
Having said that, a raucous support and making the stadium feel as unwelcoming as possible for the away team is part and parcel of "home advantage" in the game and must be made use of—in the right way.
Manchester United and Liverpool supporters have no love for each other, and that needs to manifest itself in the best way possible—support of their own teams—during the forthcoming game, leaving all other issues aside.
The rivalry is alive and well, and it should be a spectacular occasion at Anfield.