The Red Devils were comprehensively beaten 2-0 by Newcastle United at the weekend, while the Bees were pegged back three times in a 3-3 thriller with Brighton & Hove Albion.
Match preview
In strikingly similar fashion to Arsenal's defeat to Newcastle at St James' Park last term - which all but ended the Gunners' hopes of Champions League football - Man United were outclassed, outfought and outplayed by their counterparts in black and white on Sunday afternoon.
Revenge was the name of the game for Newcastle a few weeks on from suffering EFL Cup final heartbreak at the hands of Erik ten Hag's men, but second-half headers from Joe Willock and Callum Wilson prolonged Man United's recent problematic patch in the top flight.
Both Ten Hag and a disgruntled Luke Shaw admitted that Newcastle's "passion, desire and hunger" heavily outweighed that of Man United, who have now dropped below their North East counterparts into fourth place in the Premier League table, gleaning just one point from their last three fixtures in the top division.
By the close of play on Monday, Man United could find themselves out of the Champions League places entirely if Tottenham Hotspur avoid defeat against Everton, but the Red Devils will have played two games fewer and therefore still have their Champions League destiny in their own hands at this pivotal point.
With the Europa League and FA Cup taking centre stage before the international break, it is fair to say that Ten Hag's men have somewhat neglected their top-flight duties, and the Red Devils could fail to score in four successive Premier League games for the first time in their history this week.
However, none of the hosts' last 12 Premier League matches at Old Trafford has ended in defeat, and eight goals conceded at home is the best defensive record of its kind in the Premier League, while Brentford could have done with a lesson or two in keeping the back door shut at the Amex.
Three times Thomas Frank's side propelled themselves into the ascendancy down south, and three times the Seagulls roared back, as the battle between two European outsiders lived up to the billing and then some - Pontus Jansson, Ethan Pinnock and Ivan Toney left with another goal on their records.
A point was enough to lift Brentford into seventh place above a disjointed Liverpool side - although they have played a game more than the Merseyside giants - and Frank's men only have two wins to boast from their last seven top-flight fixtures - failing to beat relegation candidates Everton and Leicester City in that period.
However, defeat at Goodison Park represents the Bees' only loss from their last 16 in the Premier League, and few Red Devils fans will need reminding of the 4-0 embarrassment inflicted on them at the Gtech Community Stadium during the summer months.
The Bees followed that up with a stellar 2-1 triumph at the home of Manchester City - no team since Arsenal in 1991 have won away at both Manchester clubs in a single campaign - but Frank oversaw a miserable 3-0 loss at Old Trafford towards the end of last season.
Manchester United Premier League form:
D
W
W
L
D
L
Manchester United form (all competitions):
L
W
D
W
W
L
Brentford Premier League form:
D
W
L
W
D
D
Team News
Being blessed with no fewer than four injury boosts before the trip to St James', Ten Hag welcomed all of Raphael Varane, Marcus Rashford, Marcel Sabitzer and the luckless Anthony Martial into his ranks for that defeat - the latter should now come into contention for a start over the ineffective Wout Weghorst.
However, a trio of ankle victims in Alejandro Garnacho, Tom Heaton and Christian Eriksen remained sidelined alongside Donny van de Beek (knee), while Casemiro serves the penultimate game of his four-match domestic ban, restricting Ten Hag's options in the centre of the park again.
Right-back Aaron Wan-Bissaka was also a late absentee from Sunday's game due to illness, but should the defender make a rapid recovery, he could be one of a few alterations alongside Fred and Jadon Sancho.
While Man United continue to cope without a suspended midfielder, Brentford welcome lynchpin Shandon Baptiste back from a one-game ban, although Vitaly Janelt is still struggling to shake off a knee problem.
Kristoffer Ajer (calf) and Keane Lewis-Potter (knee) are also unlikely to play again until the final few weeks of the season, but Frank has no fresh concerns to report from the six-goal stalemate with Brighton, where Jansson marked his first Premier League start since October with a goal.
The Swede could therefore continue in a three-man backline for the visitors - assuming he is fit enough - but Yoane Wissa will be eyeing Mikkel Damsgaard's spot on the left.
Manchester United possible starting lineup:
De Gea; Wan-Bissaka, Varane, Martinez, Malacia; Sabitzer, Fred; Sancho, Fernandes, Rashford; Martial
Brentford possible starting lineup:
Raya; Mee, Pinnock, Jansson; Hickey, Jensen, Norgaard, Henry; Mbeumo, Toney, Wissa
We say: Manchester United 2-2 Brentford
Brentford tend to thrive when the going gets tough against Big Six clubs, and Frank's side ought to ask several questions of the Man United backline, especially with a day's extra rest to enjoy.