Ferguson made 10 changes from the side that drew 3-3 with Everton in the Premier League on Saturday for Tuesday's Group C opener with Rangers, and paid the price as he watched his team being suffocated in attack to be held 0-0 by the visiting Scots.
Fielding a weakened side suggested Ferguson's mind was on Sunday's league match at home to Liverpool but fans might find that hard to swallow when some of Roy Hodgson's players have acknowledged they may struggle to make the top four this year.
"The criticism will be, 'Why didn't I play a stronger team?," said Ferguson. "I think I played a very strong team. People forget eight of them played against Chelsea in the Community Shield (at Wembley in August)."
The season-opening Community Shield between the league champions and FA Cup winners may be a trophy but it is held in even lower regard than the League Cup, a competition where it is common practice for big teams to give fringe players a start.
Of course, most clubs do not have a second-string side bursting with international players and Champions League winners like the one Ferguson selected against Rangers.
Rangers manager Walter Smith wistfully pointed out that most of the lineup would be top choices in any Premier League side.
But the point is United have even better weapons in their arsenal and Internet fan forums posted lively debates about why in-form striker Dimitar Berbatov and the creative Paul Scholes were left out, with some saying Ferguson had overrated his own squad rather than underrated Rangers.
LONG-RANGE SHOTS
They were disjointed in midfield with Park Ji-sung giving the ball away and Darron Gibson offering little more than long-range shots.
Javier Hernandez was enthusiastic up front but lacked a finishing touch of Berbatov's quality and Antonio Valencia was ineffectual on the wing before a horrific injury ended his game and probably his season.
Fans questioned the need for squad rotation so early in the season and bemoaned the fact it made qualifying from the group harder because there was more pressure to pick up a win away from home.
Ferguson says he thinks United need 10 points from the six group matches to progress to the knockout stage. Valencia and Bursaspor are the other teams in the section and the Spaniards showed they meant business with a 4-0 rout of the Turks on Tuesday.
All the clues were there that Rangers could sneak a point as their only two points in last year's competition came from away games.
They deployed an eight-man defence that frustrated United and made for dull viewing. Even the Rangers fans who started the evening with some half-hearted booing of Wayne Rooney over his private life lost interest on a quiet night at Old Trafford.
The noise should return on Sunday for the visit of traditional rivals Liverpool and the return of United's big guns.
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