The Red Devils suffered a humiliating exit at the hands of Basel in the group stages of last year's competition - but there is no chance of that happening again, insists manager
United were eliminated from the competition at the earliest stage after being beaten by the Swiss side, which capped off a poor performance in a group that the then-defending Premier League champions were expected to win, with Benfica and minnows Otelul Galati the other teams in their section.
The Red Devils had previously reached the final in three of the previous four editions of the competition - and their earky exit proved even more damaging than it initially seemed, as Nemanja Vidic missed the rest of the season with a knee injury picked up against Basel - and Sir Alex has warned Europe that his side will not make the same mistakes again.
The Scot told reporters: "That definitely won't happen next season. There's no chance of that.
"Over the last few years, we've used the group stage as an opportunity to play the youngsters. Last season it backfired on us.
"We changed the team too much. We won't be doing that this season.
"I just think we were careless. The killer was the game against Basel at home [which ended 3-3]. We could have been 5-1 up at half-time but were really careless in that game.
"We were unlucky against Benfica at home because we played well, but that Basel game was a real killer for us. They were just an ordinary team and they showed that when they played Bayern Munich.
"They were lucky against Bayern at home [Basel won 1-0 in the first leg of their last-16 tie] and they were lucky against us also. Bayern battered them [winning the second leg 7-0]."
Ferguson is confident that he has a squad capable of emulating the United teams of 1999 and 2008 by delivering another Champions League crown to Old Trafford next season.
When quizzed on the subject, he replied: "Oh yes, definitely. Absolutely. There's no doubt about that.
"Don't forget that Nemanja Vidic only played six games for us [in the Premier League] last season, while Darren Fletcher was a loss too."