KEY POINTS:
Let's face it, if Sir Alex Ferguson had to choose between a result against Chelsea or one against Barcelona it would be the latter every time.
Which must have been the compromise he made with himself when he sketched out a team sheet that did not include Cristiano Ronaldo, Patrice Evra and, to a lesser extent, Paul Scholes and Carlos Tevez.
It has been Ferguson's dream for years, the ability to roll out under-strength teams in certain games to do the business and give the A-listers a break.
It has rarely worked on any level.
He has tried playing reserve sides in the FA Cup against Exeter City (2005) and Burton Albion (2006) and in the Carling Cup against Southend (2006) and it ended in two draws and a defeat.
He left out the best player in the League and the best left-back in the country and United faltered.
The Manchester United manager did what he thought was right, and there were some very good reasons for resting Ronaldo, but it seemed destined to backfire.
What did Saturday's United team selection say to Chelsea? It said that United would try to win this game, or at the very least draw it, at less than their full capacity.
Let's say that without Ronaldo and Evra, United are reduced to 80 per cent of their potency.
Avram Grant, on the other hand, had no choice but to throw at United the very best that he had at his disposal to win the match.
Managers keep telling us that it is the tiny margins that make the big differences in games such as these.
And a United team without Ronaldo and Evra seems like a significant enough margin to make a difference against an opponent like Chelsea.
Ferguson must have made the decision partly on the basis of how his United team - without Wayne Rooney and Ronaldo - disposed of Roma at Old Trafford this month.
The comparisons are a little misleading, Roma missed a penalty early on that could have changed the game and, anyway, the Italians, dispatched 7-1 a year earlier, are still miles behind Chelsea.
Let's not exaggerate.
United playing Chelsea without two key players is by no means the football equivalent of asking Lewis Hamilton to win the Barcelona grand prix in a 1983 Austin Allegro but it definitely makes a difference.
Ferguson now contemplates his next two league games against West Ham and Wigan knowing he has to win both to be sure of the title on goal difference.
It is not such a bad situation.
If Rooney and Nemanja Vidic are fit to play against Barcelona, and then if United progress to the Champions League final, Ferguson will be justified in saying that his decision to rest Ronaldo was worth it; worth even losing to Chelsea.
But the result demonstrated that no one, not even United, can rest key players in the big games.
Only Ferguson and his staff know when a player needs a break. They will have ProZone statistics detailing the exact distance covered by an individual, they see him training every day, but does Ronaldo really look tired? Rooney's goal notwithstanding it would seem that he was the stronger candidate for an afternoon off.
Ronaldo's lacklustre evening at the Nou Camp last week must have convinced his manager that something had to give but generally the winger has looked immune to all the normal frailties n tiredness, injuries, indifferent form n that afflict most mortals.
The aftermath, in particular Ferguson's unholy attack on the refereeing performance, was more unedifying.
The referee Alan Wiley awarded Chelsea a penalty for hand-ball against Michael Carrick because the ball was struck from far enough away from the midfielder for him to take evasive action.
"But he's running towards his byline and his hand's down there [by his side]," protested Ferguson, seemingly suggesting that Carrick is physically incapable of moving his arms upwards or downwards while running.
It is a defence of a kind, but it is not much of one.
He was also unhappy about his team's treatment from the referee in the game against Chelsea, as well as those against Middlesbrough and Portsmouth in the FA Cup; "diabolical" and "ridiculous" were a couple of the words that Ferguson used to describe the decisions.
He argued that Michael Ballack had wrestled Ronaldo to the ground in the box late in the game and, in the words of his assistant, Carlos Queiroz: "I think it is necessary to get a gun and shoot somebody in the box to make [sic] a penalty for our side." That one is actually a tried and tested line of Ferguson's but quoting his boss shows Queiroz is listening to him.
It could not hide the fact that United were outplayed by Chelsea for long periods of the game, something which Ferguson more or less admitted to later when he had calmed down.
At times you could see Rooney indicating to Darren Fletcher to get the team moving quicker and the ball moving more fluently out of midfield and up to the lone striker.
Fletcher was one of United's better performers although the same could not be said of Nani who had a poor game and demonstrated his worrying tendency not to look up for better options when running with the ball.
Perhaps most galling for United is that they lost to a Chelsea team who could hardly be said to be playing like kings.
Grant is entitled to enjoy the moment but, all the same, there were some remarkable signs of the problems at the club.
Ballack, who scored the first with a header from a Didier Drogba cross, got in an embarrassing argument with the Ivorian over a free-kick.
Drogba complained to the bench where it was left to Steve Clarke to calm him down.
Michael Essien summed it up best by pulling his shirt over his face in embarrassment.
Rooney's equaliser on 57 minutes came from Ricardo Carvalho's uncharacteristically poor back-pass, never the less the Englishman did brilliantly well to stay ahead of John Terry and score exactly the kind of chance he has missed too many times of late.
Ronaldo was on for the late stages after Ballack scored the penalty Carrick conceded.
Ashley Cole and Andrei Shevchenko both cleared off the line.
The Portuguese winger was evidently appeased by being told that he is being saved for bigger things against Barcelona and that is exactly how United looked yesterday.
- THE INDEPENDENT