Jose Mourinho's side was outclassed at the Mestalla in a 2-1 defeat to Valencia and will now come up against Europe's very best.
Had United got a very attainable three points from Spain, they would have returned to Old Trafford as Group H winners.
First-place Juventus had suffered a shock defeat away to Young Boys, opening the door for Mourinho's men.
Instead, they slammed it shut themselves and will come up against the mightiest clubs across the continent.
Possible opponents include Barcelona, Real Madrid, Bayern Munich, Paris Saint-Germain, Borussia Dortmund and Porto.
And United fans were blaming Mourinho on social media for the missed opportunity.
Twitter user Tommy Roberts wrote: "I would lay money on it that the group winners are hoping they draw @ManUtd in the next round.
"This is how far our club has fallen. What is the special one teaching them in training every week? He's finished, get him out of the club."
Tweeter @NagMoleMUFC, known only as Paul, reflected: "It really isn't going to matter who we draw, we go out."
And @_TheDevilsDen forecast only one way in which United progress: "Unless we get Porto in the #UCL draw, we're as good as out."
Mourinho may prefer a reunion with Porto, the club he led to Champions League victory in 2004 which is deemed the weakest of the bunch.
But whatever the outcome in Monday's draw at Uefa's HQ in Nyon Switzerland, United could have had an easier path in the knockouts.
Defeat at the Mestalla was confirmed when Phil Jones' miscommunication with Sergio Romero led to the defender scoring an own-goal.
That put United two behind after Carlos Soler had given Valencia the lead 17 minutes into the match.
Source: Read Full Article