"Ryan Giggs, in the first half, provided something and some parts of his game were good but what we needed was someone to be there all the time but they defended quite well.
"We had plenty of time and we had some half-chances, which we maybe should have done better with.
"It was a disappointing performance and some individuals will feel it themselves. It's very difficult to put a finger on every part of the game."
Ferguson also conceded United missed the protective presence of Darren Fletcher in midfield - the Scot was suspended after being harshly sent off against Arsenal in the semi-final.
"He is one big-game player," said Ferguson. "It was a loss but they had losses also and it is difficult to measure how big a loss it was."
On Guardiola, who has guided Barcelona to a treble trophy haul of the Spanish league title, domestic cup and Champions League, Ferguson added: "It is a great achievement as a coach in his first year. Well done. Fantastic. Everybody enjoys their football and it is great credit to him."
We controlled the game - Guardiola
Centre-back Rio Ferdinand agreed with Ferguson that the Catalan giants were the better side, saying United did not "play well individually or collectively".
Ferdinand commented: "You've got to give credit to Barcelona, they played well. We needed to play our best football and we didn't produce it.
"The first goal was a sucker punch, we'd had some good chances. They were two soft goals and we could have done better leading up to them and I could have done better with my positioning but we've got no excuses, they were a better team."
Goalkeeper Edwin van der Sar conceded Samuel Eto'o's 10th-minute goal gave Barcelona the confidence to retain the ball and dictate the tempo of the match.
"We have come from behind plenty of times before, so the goal itself was not an issue," said the Dutchman.
"But what it did was to allow them to start playing a little bit. In situations like that you have to try and keep possession but at times I felt we lost it a little bit too easily."
United winger Cristiano Ronaldo described the defeat as "one of the biggest disappointments of my career".
Everything went wrong - Ronaldo
"We were always confident before the game but unfortunately we couldn't do it," said the Portugal international. "It is always bad when you lose a final but we didn't play well.
"We did OK in the first 10 minutes but you have to say Barcelona deserved to win."
Striker Wayne Rooney was equally distressed at United's first European Cup final defeat, adding that Iniesta was the key to Barcelona's victory.
"Barcelona scored two good goals and, unfortunately for us, they came at good times," said the Englishman. "That made it very difficult for us.
"Barcelona are a brilliant team. Andres Iniesta is the best player in the world in my opinion. If you don't take your chances against them, they will punish you and that is what has happened.
"It is very disappointing and the feeling at the moment is not a good one. We are hurting but we have to forget it and look forward to next season."
They turned up and played some great football - we didn't really
United captain Ryan Giggs thought his side "probably had more chances than Barcelona" but that their rivals were well worth the victory.
"At times Barcelona can make you look silly because they keep the ball so well," said the veteran midfielder, who was playing in his third Champions League final.
"At times we maybe chased it and didn't keep our shape as well as we should have but, still, we created chances - and probably more chances than Barcelona.
"We said whoever turned up on the night would win and that proved to be the case. They turned up and played some great football - we didn't really.
"I think if we had gone a goal ahead, we're capable of keeping the ball like they are but credit to them, they deserved it."
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