Despite dominating almost the entire game, Sir Alex Ferguson's men rarely looked like making their pressure tell.
Paul Robinson needed to make two excellent saves to deny Antonio Valencia before half-time, but afterwards, with United so desperate for the points, the former England number one had surprisingly little to do.
Not for the first time recently, Dimitar Berbatov was a major disappointment and the fact Rio Ferdinand was feeling his groin towards the end suggested a problem Fabio Capello will not want.
There are no worries for Chelsea though, who still lead the Red Devils by a point, with a game in hand, knowing the main danger to their championship aspirations now lies much closer to home, at Arsenal.
Although United had not actually lost their last three games, that is how it felt.
Even Sir Alex Ferguson spoke in those terms ahead of the clash, a 3-2 win over Bayern Munich apparently not enough to take away the feeling of desolation an away-goals Champions League exit.
In such circumstances, a rip-roaring response would normally be anticipated, the players sent out to represent Ferguson eager not to let their manager down.
On this occasion, such urgings fell on deaf ears.
Although they gradually took control, on a sunny afternoon, the first half took on the air of a pre-season contest.
On Blackburn's part, the lack of urgency was understandable given their position firmly wedged in mid-table.
For United it was an altogether different story.
After all, they are still supposed to be playing for the title.
Indeed, while it might only be because Chelsea were on FA Cup duty yesterday, the prize for victory was a place at the top of the table.
Despite their torpor, United should have been in front at the break.
Valencia was the recipient of both clear-cut chances.
The first was created by Federico Macheda, making his first Premier League start of the season.
Valencia charged on to the young Italian's neat pass with purpose and let fly with a powerful effort that was heading for the bottom corner until Paul Robinson made a fine low save.
Berbatov was the architect of the second.
Ferguson had little choice other than to declare his trust in the Bulgarian given Wayne Rooney was missing with an ankle injury.
But it was a largely unhappy afternoon for United's £30.75million record signing, who was reduced to arm-waving and head-shaking as his meaningful contribution until he threaded a pass through to Valencia.
The South American eagerly latched on to the chance but again Robinson denied him, this time at close quarters.
As there was no immediate injection of focus or direction after the interval, so Ferguson decided to sacrifice Giggs, who admittedly had been fairly anonymous.
Outstanding earlier this season, the Welshman has struggled for form since recovering from his broken arm.
His replacement, Darron Gibson, is at least prepared to shoot, as he proved in midweek.
The Irishman's aim was a bit askew. But at least he tried as United's season began to crumble around them.
That Scholes chose to play on as Berbatov was down and apparently injured after a crunching collision with Nelsen seemed to tell its own story about the discontent in the United camp.
Friction between Edwin van der Sar and Ferdinand would be less easy to understand, although there was a clear lack of communication between the pair as, under no pressure, England's new captain booted a ball out for a corner the keeper was about to collect.
Berbatov's unhappy afternoon continued when he failed to test Robinson, having been set up by Neville and then fired wide after a long throw from the full-back bounced straight through the Blackburn defence.
It was almost an epitaph for his entire United career, and when Neville's late scuffed effort rolled wide, the vast travelling support knew their season was destined to end in disappointment.