There are few guarantees at Old Trafford tomorrow when the Premier League waits to be claimed by one of the two best teams in England.
However, it should be immensely encouraging to the embattled, marginalised, and even the sometimes patronised Carlo Ancelotti that he owns one of them.
It lies in the superior potential for destruction invested in a Didier Drogba playing in the right place, the right formation and with an optimum level of the confidence that came from the status that was stripped from him by the arrival at Stamford Bridge of Fernando Torres.
We are not just talking a single selection issue here. We are touching the basic reason why Chelsea's record, for all the resources heaped upon them by Roman Abramovich, is so sporadic when compared to the relentless accumulation of United success.
We are discussing what happens when one manager is given the brief that has always been a pre-condition of the ability to do the job — and a whole series of them know they are obliged to live from result to result, mood swing to mood swing, without ever having the authority that long-term breeds both respect in the dressing room and cohesion and certainty on the field.
In the first category read Ferguson; in the second, Ranieri, Mourinho, yes eventually even Mourinho, Grant, Scolari and Ancelotti.
Yet Ancelotti, who was yesterday denying that a trip to Italy had anything to do with concluding a move to Roma, has one shining opportunity tomorrow to create a glorious interlude in his Chelsea purgatory. He can take a page from the battle-stained book of the Spanish Civil War heroine La Pasionaria, who declared, “Comrades, it is better to die on your feet than live on your knees.”
For Ancelotti this may simply require him to stick to the formation he finished with on the recent night when United expelled Chelsea from Europe — a task which suddenly became more hazardous when Drogba appeared in place of Torres and scored with trademarked pace and aggressive instinct.
Ancelotti won a superb double at the first attempt with Drogba operating in a system in which all his power, and a willingness to run prodigiously which was first employed so effectively by Jose Mourinho before the arrival of Torres' precursor, Andriy Shevchenko, and then he was building from the ruins which came with the morale-sapping dismissal of his assistant Ray Wilkins when the Spaniard came down in his parachute and, for all intents and purposes, might have landed on a high ledge somewhere along the Fulham Road.
So now Ancelotti has to re-exert his football values — for what has he to lose but the perceived role of someone for the executive office to kick around?
United were poor against Arsenal but when Ferguson sent in the back-up men against Schalke he was making a statement of supreme confidence, keeping key troops fresh for tomorrow's action.
It was a flexing of the psychological muscles permitted a man encouraged to believe that he is charge of all he surveys.
That there is likely to be a trickle down effect in the United dressing room seems like a reasonable presumption.
Chelsea may be wearing thin at certain joints but unquestionably they retain the ability to produce football of both power and invention.
It wasn't so visible against Tottenham last weekend, but then nor was United's penchant for re-inventing themselves in the middle of a rank performance.
Where it leaves us is pondering the eddies of form and nerve and the capacity of players like Drogba, Wayne Rooney and the young Mexican firecracker Javier Hernandez to inflict themselves on the most important game of the season.
It is impossible to believe that it will be anything but close, and clammily so, but in the end you have to go with an instinct, a sense of which fighter has most reason to believe in himself and the ultimate capacity to see off the other man.
When you look at it this way, United, contemplating another European Cup final after banishing Chelsea along the way, seem to have the edge.
Their greatest concern is surely Didier Drogba and it is something Ancelotti is unlikely to forget when he writes down his team.