Manager Alex Ferguson blamed Manchester United's failure to keep possession for the 2-1 Champions League defeat by Benfica which cut short their campaign in Europe.
Wednesday's reverse, which left them bottom of Group D, dealt a hammer blow to United's season as they failed to even qualify for the UEFA Cup.
Though Paul Scholes gave the visitors a sixth-minute lead, Benfica levelled through Geovanni and grabbed the winner from Beto's deflected shot in the 34th minute to sail into the knockout stages as group runners-up behind Villarreal.
Pinpointing the trouble faced by a United side whose passing was often scrappy, Ferguson told reporters: "We got off to a good start but I thought we gave away possession far too easily.
"If you give away possession like we did in the first half you don't deserve to win. I think that was the main problem.
"In the second half, I'd give us 10 out of 10 for effort and determination but when you're chasing a goal frustration and desperation come in.
"It was understandable that we got too anxious at the end...we were too keen to win, we lacked composure in the last third."
Defeat ended United's record of nine consecutive seasons in the knockout stages of the Champions League, including their final victory in 1999.
"We're disappointed," said Ferguson. "It's a low point in the sense that we've always qualified for Europe."
United's failure will also deny the club valuable revenue from European competition following the 790 million pounds ($1.37 billion) takeover by U.S. tycoon Malcolm Glazer.
The takeover has made Ferguson's own future at the club a matter of media speculation in recent months, particularly when the team suffers a setback.
Refusing to be drawn on his own situation, Ferguson said: "We've got a job to do at this club, rebuilding, and we'll carry on with that...I've confidence in my players."
As for the winners, he said: "I can't deny Benfica the result in the sense that for 15 minutes in the first half they played well and in the second half they defended well.
"They had one or two counter attack moments in the second half when they could have finished us off.
"I don't think it was an unfair result but don't think it would have been unfair if we'd have got an equaliser because we had most of the pressure in the second half."
Benfica's Dutch coach Ronald Koeman was delighted with his team's response to Scholes's early goal.
"The reaction of the team was fantastic because if you're 1-0 down at that level and go on to score two goals that's unbelievable," he said.
"The second half was a bit different because Manchester were trying everything. Maybe they were playing the long ball a bit too much, our team can defend very well and we have strong players in central defence.
"It was a pity we didn't score a third goal because we had the opportunities in the second half...but it's a great day for Benfica."
Geovanni told Portuguese state TV RTP: "At the right time, God is constant. God put it in and gave me the chance to put Benfica into the next phase."