Darren Fletcher was perhaps the perfect player to disrupt Barcelona's possession football, and Sir Alex Ferguson's fears before the game that the suspended midfielder would be a great loss sadly proved prophetic.
The Reds boss recognises that Barcelona also had players missing through suspension, but from a United point of view Fletcher would have been key in disrupting the flow of passes from Andres Iniesta and Xavi to the front three of Eto'o, Henry and Messi.
"I thought before the game it may have been a problem," said Sir Alex.
"I knew it might count against us because he is a big-game player and he was a big loss. It's difficult to say how big, and they had players missing too, but it showed for us tonight."
Fletcher's ability to cover every blade of grass in the middle of the park would have been an asset as United tried to regain possession - but keeping the ball was also a problem.
"The simple reason we lost was possession," Sir Alex added. "You have to wait minutes to get it back off Barcelona but when we did get it, we didn't do anything with it.
"That was the disappointment, our use of the ball when we had it.
"We recognised beforehand their strength was their central midfielders. It wasn't really Messi who was the problem. It was Iniesta and Xavi. They can keep the ball all night long.
"You have to give credit to a very good Barcelona team. If they get in front of you they are very difficult to beat."