Ole Gunnar Solskjaer's side have dropped 11 points from their last six Premier League games, slipping down towards the group of top-four challengers rather than tussling for top spot.
Now, Theatre of Dreams favourite Steve Bruce is back in town, with two wins in the Magpies' last four outings - as many as they racked up in the previous 11.
Boss Bruce boasts just one win from 25 managerial meetings with his former club, that being a 1-0 victory at St James' Park last term.
As the former centre-back will know, Newcastle are an inconsistent opponent of Man United's, meaning the Mancunians have a fair amount of fond memories when playing them.
Planet Sport takes a look at some of Man United's star showings against the Toon Army.
Man United have met Newcastle 170 times over 137 years, winning 88 of their contests to give them a victory rate of 51.7%.
The Red Devils have hit 335 goals in those, conceding 240, contributing to 39 draws and 43 losses.
Back in October, the 20-time English champions won 4-1 at St James' Park to follow up another 4-1 thrashing on Boxing Day of 2019 at Old Trafford.
That was the last time the Magpies travelled to the Theatre of Dreams and in both games, took the surprise leads.
Those big wins aren't anomalies, though, with plenty of triumphs to reminisce over or rue, depending on your allegiance.
Top five performances
Manchester United 6-0 Newcastle United
January 12, 2008
On their way to the second of three successive top-flight titles, Sir Alex Ferguson's side hit caretaker manager Nigel Pearson's players for six.
Cristiano Ronaldo bagged his first and only hat-trick for the Red Devils, with two from Carlos Tevez and one from Rio Ferdinand making it a rough trip for the Toon faithful - even with Wayne Rooney squandering opportunities.
Having recently sacked Sam Allardyce, Newcastle supporters called for the appointment of legend Alan Shearer in the stands but the day was more about CR7, whose three strikes went into his personal-best 31 league goals in a season as the men from Old Trafford romped their way to title number 17.
Magpies fans eventually got their wish the following season - albeit after four other managerial appointments - but Shearer couldn't save them from the drop in 2009 once Ronaldo was a Madridista.
Manchester United 5-3 Newcastle United
November 23, 2002
Matches between these sides have always produced goals and entertainment, with this 2002 clash being a prime example.
Ruud van Nistelrooy hit a hat-trick of his own, with Paul Scholes and now gaffer Solskjaer, who scored his first against the North East outfit, sandwiching the Dutchman's treble.
Amid a difficult few years for Ferguson, with Arsenal and Chelsea beginning to assert themselves, Van Nistelrooy was a large part of why the red side of Manchester could call themselves champions in 2003 - the only year in five from 2002 to 2007, following three on the trot at the turn of the century.
Although he didn't take the limelight or a point back north, Shearer struck his 100th PL goal for Newcastle, becoming the first player in the division's decade long history to reach a century of strikes for two different teams (the first with Blackburn Rovers).
Manchester United 4-3 Newcastle United
December 26, 2012
The year 2019 wasn't the first Boxing Day bonanza that the Red Devils have enjoyed over the Magpies, as the Old Trafford faithful were given a late Christmas present seven years prior.
The teams traded three goals each, back and forth, one after the other, until the 90th minute.
Javier Hernandez came up with a winner following goals from Golden Boot winner Robin van Persie, Patrice Evra and Jonny Evans (who scored at both ends) and Ferguson described it as a 'phenomenal' comeback effort.
Manchester City's loss on the same day meant United stormed to a seven-point lead heading towards their most recent and Fergie's final title triumph.
Alan Pardew's outfit would go on to finish 16th, failing to build on a campaign in which they made it to fifth, their highest finish of the much-maligned Mike Ashley era.
Manchester United 3-2 Newcastle United
October 6, 2018
Another Old Trafford comeback now as Jose Mourinho saved his bacon as boss thanks to a late rally two seasons ago.
Having begun the 2018/19 term terribly, Man United were suffering woes on and off the pitch as the end of the Special One's time was nigh - two months to be exact.
Kenedy's goal after seven minutes and Yoshinori Muto's on the 10-minute mark gave Rafael Benitez's men a shock early lead in the Saturday evening kick-off.
However, they failed to hold strong as scrumptious strikes from Juan Mata, Anthony Martial and Alexis Sanchez rescued three points for the Red Devils.
With Ashley in attendance, the owner witnessed the team he presides over suffer their worst start to a top-tier season since a win became worth three points in the English pyramid, with just two from their opening eight games.
Newcastle United 0-4 Manchester United
April 5, 2014
Between two titanic Champions League quarter-final ties against Bayern Munich, David Moyes' Man United strolled to a fourth consecutive away league win for our final entry.
January signing Mata bagged a brace either side of the break in the North East, with Hernandez and then 'next big thing' Adnan Januzaj adding in the second half - the latter arguably being the pick of the bunch because of Mata's magic to assist.
The Spainiard's first goal was a delightful free-kick on 39 minutes and his second, a simple shimmy to slot into an open net, as Moyes made numerous changes with Europe in mind.
It was the last high of his 10 months at the helm, though, as the Red Devils would go on to lose in Germany on the Wednesday and the Scot would subsequently lose his job later that month.
Tip of the Fixture
A third successive 4-1 win for Manchester United in this fixture is priced at 13/1 on paddypower.com.
In-form Scott McTominay 4/1 to net any time to make it four successive home games with a goal for the midfielder.
(Odds correct at time of writing, subject to change).