Those beatings have prompted the same question among many United fans: Just how is the team going to prevent another thrashing by Bayern Munich, currently the best team in Europe, in the first leg of the Champions League quarterfinals?
For, arguably the first time in the Champions League era, United heads into a home match as the underdog -- and for good reason.
Bayern is the reigning European champion, the recently anointed German champion and has only lost two games in all competitions this season -- in the German Super Cup and against Manchester City in the Champions League when its place in the knockout stage was already guaranteed.
United, meanwhile, is enduring its worst season for some time and is languishing in seventh place in the English standings, with doubts hovering over the suitability of its manager and a slew of its players.
Rarely can United, an established continental heavyweight, be written off so dismissively for a European game.
Here are five things to know about Tuesday's match:
1. Chasing records
After successfully defending its Bundesliga title in record time last week, Bayern Munich is looking to become the first side to retain the Champions League trophy in the competition's modern format.
That is one of a host of milestones in its grasp.
Bayern remains on course to emulate last season's treble (league, German Cup, Champions League) and even better it. Saturday's 3-3 draw at home to Hoffenheim ended Bayern's Bundesliga-record winning run of 19 games but the side remains unbeaten in a league-record 53 games.
Bayern could become the first side to complete a Bundesliga season unbeaten in 51 years of the league, while the team looks set to eclipse last year's record points total when it finished with 91 points. Bayern now has 78, with 18 points still to play for.
2. Memories of 1999
Ever since United and Bayern were paired in the draw for the quarterfinals, there have been endless clips of the memorable final at the Camp Nou in 1999 that was settled in the English side's favour by two injury-time goals.
Those were the glory days for United in the trophy-laden Alex Ferguson era -- and they couldn't be further away for United supporters.
This season -- the first post-Ferguson -- has been tough and one that manager David Moyes will be glad to see the back of.
"It's been a difficult season for us," Moyes said, "but we can go a long way to doing an awful lot better if we can get a result on Tuesday."
Every win seems to be quickly followed by a new setback for Moyes in his first year at Old Trafford. So he may be slightly concerned that United heads into the game on the back of a 4-1 victory over Aston Villa in the league.
3. Bye-bye champions league?
United should make the most of Tuesday's match -- it could the last one in the Champions League at Old Trafford for some time.
Moyes' side is 10 points adrift of the top four in the Premier League, so is almost certain to miss out on Champions League qualification through its league placing. That means it can only qualify for the competition by winning it this season.
Given the rebuilding job that Moyes is planning, there's no guarantee that United's absence from the Champions League will be just the one season -- as the recent demise of Liverpool over the past four years has shown.
4. Bayern blip
Bayern coach Pep Guardiola has rotated his squad heavily this season and he rewarded his side for winning the Bundesliga in midweek by resting David Alaba, Jerome Boateng, Toni Kroos, Philipp Lahm, Thomas Mueller, Arjen Robben and goalkeeper Manuel Neuer for the league match against Hoffenheim on Saturday.
The result? Bayern allowed the visitors to come back from two goals down to snatch a 3-3 draw -- the first time since a 1-3 loss to Borussia Dortmund in February, 2011 that Bayern conceded three goals in a Bundesliga game at home. It was only the third time the side had dropped points in 28 league games this season.
"We're not favourites against Manchester on Tuesday if we play like we did in the second half," Guardiola said.
5. Team news
Bayern will be without Thiago Alcantara for the quarterfinals -- and the semifinals, should the team progress -- after the midfielder tore ligaments in his right knee during the first half against Hoffenheim.
Guardiola, however, has enough strength in depth in its quality-packed squad to compensate for the loss of the talented Spaniard.
United has been hit harder by the loss of Robin van Persie, who is likely to be missing for the next month with a left knee injury. The Netherlands striker had scored 23 goals in 29 games for club and country this season.
Like Bayern, United rested some key players at the weekend. Patrice Evra, Michael Carrick and Rio Ferdinand are likely to return to the starting team, while 40-year-old midfielder Ryan Giggs may be recalled after his impressive display in the second-leg victory over Olympiakos in the last 16. Juan Mata is cup-tied.