Since their last Premier League title win in 2010, there has been a growing clamour for Chelsea to reinvigorate their squad.
Neither Carlo Ancelotti, nor Andre Villas-Boas managed to do it but Roberto Di Matteo has, without really trying.
The catalyst was Didier Drogba's departure for China in the wake of his match-winning heroics in last May's Champions League final.
Nicolas Anelka had already left, Michael Essien followed, on loan to Real Madrid, and Frank Lampard has struggled to find form even before his latest injury, so the opportunity for change came far easier than anyone expected.
And, just as owner Roman Abramovich wanted, in place of the physical approach for which Chelsea were so noted have come smaller alternatives, as Juan Mata, Eden Hazard and Oscar produce the rapier attacks rather than use a sledgehammer.
"Chelsea always had that alternative route of playing with Drogba up front," said Ferguson.
"They could play it long or they could play it through midfield.
"Now it's straightforward. It's through midfield all the time.
"But it's not an easy system to deal with. Oscar and Hazard are similar type players. And with Mata as well they all play in behind the main striker.
"We just have to find a way of dealing with it."
Prior to Tuesday's Champions League defeat in Donetsk, the system had been an unqualified success.
They have so far dropped just two points in the Premier League - a goalless draw at QPR - reached the last 16 of the Capital One Cup and steered themselves into a handy position in the Champions League.
Ferguson might hope that trip to Ukraine has brought some element of doubt to the Blues camp.
For there will be none to come from a remarkable record at Stamford Bridge, where they have not lost in domestic combat to Sunday's opponents since 2002.
"It's an amazing record," said Ferguson.
"It will change - sometime. Hopefully on Sunday.
Despite that lack of success, it could hardly be claimed United's visits to the King's Road have been uneventful.
There was the post-match battle between Patrice Evra and Chelsea groundsman Sam Bethell in 2008 that saw the Frenchman hit with a four-match ban.
Two seasons ago, Ferguson was given a five-match touchline ban following a rant at the performance of referee Martin Atkinson during another defeat.
Last term, in a quite amazing game, United hauled themselves back from three goals down only to need an astonishing save from David de Gea in stoppage time to preserve a point.
"In the main I don't think we've played badly," said Ferguson.
"We have actually played well in the games we have lost only to get bad decisions against us.
"Last season we did really well to rescue it after being 3-0 down and should have won it really."
"They could also have lost it though."
In that single save from Mata in stoppage time, De Gea proved why Ferguson was willing to spend £18million signing him from Atletico Madrid and why, for all the doubts over his size and failure to command his box, United will persevere.
"His strength is shot-stopping," said Ferguson.
"At the moment you would say he's a goal-line goalkeeper, there have been plenty of those over the years.
"The area which we are looking at is his strength. He's getting stronger all the time and he is already very quick, so he is getting there."
United will be without midfielder Shinji Kagawa, who is facing between three and four weeks on the sidelines with a knee injury sustained during Tuesday's Champions League win over Braga.
However, Chris Smalling has returned to training after his broken metatarsal and there is an outside chance he could be involved.