The Red Devils succumbed top spot last weekend to Chelsea after a disappointing 2-0 defeat to arch-rivals Liverpool.
Rather than the obvious pain of defeat, it will be the manner in which United tamely allowed an out-of form Liverpool - without inspirational skipper Steven Gerrard - to turn them over without so much as a fight that will have hurt Sir Alex Ferguson the most.
However the Scot will likely have consigned the defeat to the history books, instead preferring to concentrate on the visit of Sam Allardyce and Blackburn.
Rovers lie 16th in the table, two points off the relegation places and arrive at Old Trafford on the back of a 5-0 thrashing at the hands of Chelsea.
On paper the result of this encounter should be a no brainer. However, United have struggled against teams in the lower echelons of the table at home this season.
A narrow 2-1 win over Bolton two weeks ago reminded fans of the nerves they uncomfortably felt on the opening day, when only a brilliant late Ben Foster save from Christian Benitez ensured United beat newly promoted Birmingham 1-0.
Accompanied by the below-par showing in the 2-2 draw with Sunderland at home at the start of the month and you can understand why Ferguson has voiced displeasure at his side's inconsistent performances this term.
Rovers have seen their season rocked by swine flu, with rumours that Allardyce himself may have the virus surfacing this week.
The former Bolton and Newcastle boss will be hoping David Dunn, arguably Rovers' best player this season, has recovered from the illness in time to be involved at the weekend.
Red Devils newsUnited have major doubts at centre-half with Rio Ferdinand and Nemanja Vidic both struggling with calf injuries while Ryan Giggs (knee) could also miss out although Ferguson remains optimistic.
The champions may opt to field Jonny Evans and Wes Brown at the heart of the defence after both helped keep a clean sheet against Barnsley in the Carling Cup in midweek.
Park Ji-Sung is expected to be sidelined with a swollen knee for a few more weeks while Darren Fletcher (groin) is out again.
Gary Neville will definitely miss out after picking up a straight red card at Oakwell while Danny Welbeck, who opened the scoring against Barnsley, is absent with a knee injury.
Summer signing Gabriel Obertan made his long awaited debut against the Tykes after a frustrating spell out with a spine problem and he could start again.
Michael Owen gave United fresh impetus when he came off the bench against Liverpool last week and he could start instead of Dimitar Berbatov.
Owen Hargreaves has upped his training but is still not expected back until next week.
Rovers newsRovers defender Christopher Samba is still struggling with swine flu but Dunn appears to have shaken off the virus after appearing as a 70th minute substitute in the 5-2 Carling Cup win over Peterborough on Tuesday.
However Jason Roberts is the latest Rovers player to show signs that he has picked up the illness after being sent home from training on Friday
Pascal Chimbonda (calf) and Vince Grella (thigh) look likely to join Roberts on the sidelines so Michel Salgado should continue at right-back.
On loan striker Franco Di Santo was ineligible to play against parent club Chelsea last week but he should come straight back in up front after being given the night off against Posh.
Possible starting XIs:
Man Utd: Van der Sar, O'Shea, Evans, Brown, Evra, Nani, Anderson, Carrick, Valencia, Owen, Rooney.
Blackburn: Robinson, Salgado, Nelsen, Givet, Olsson, Emerton, N'Zonzi, Andrews, Pedersen, Dunn, Di Santo.