Bayern clinched a last-gasp victory in the first leg of the quarter-final when Ivica Olic netted in the dying seconds after United scored first when Wayne Rooney volleyed home in the second minute.
"We scored early but I don't think we started well at all," Ferguson told reporters.
"The disappointment for me tonight was we gave away the ball too easily. Our possession of the ball was not up to our standard. This is something we pride ourselves in," the Scot said.
"The real crux of the battle was giving the ball away," Ferguson said. "We did not need to work for the goal. It came too easily."
"We had outstanding chances to kill the tie through Rooney," Ferguson said. "That would have been lucky for us. (Keeper Edwin) Van der Sar time and time again made some fantastic saves and kept us in the game."
"It is always an advantage to score away from home so the tie is not dead. We have a strong chance. We should have a real chance of progressing but it is very tight," Ferguson said.
