While Ferguson, the Charity Shield already safely in the Old Trafford boardroom, sends his new-look Manchester United out in front of the Premiership's record crowd against Everton, Keegan's Newcastle must get back to basics when Wimbledon visit Tyneside.
The Dons were shot down in flames and style on Saturday, Eric Cantona, Denis Irwin and that David Beckham wondergoal giving United the perfect start to the defence of their crown.
Newcastle, meanwhile, were being cut down to size by Joe Royle's pumped- up troops and Ferguson, who gives home debuts to Jordi Cruyff and Karel Poborsky, has no doubts the Merseysiders will be keen to silence the majority of the anticipated 55,000-plus crowd.
Poborsky, on the bench on Saturday, comes in on the right flank following Roy Keane's knee surgery, with Beckham partnering Nicky Butt in the middle.
Ferguson believes his dug-out view of the reality of the English game means the Czech "Express Train" is both forewarned and forearmed. "Karel had a good look at Wimbledon on Saturday," said the United manager. "And it was an experience, I can tell you that.
"I think that Everton will also play the long ball. There's a little bit of Wimbledon about their style but they perhaps have one or two better footballers."
As for his new boys, Ferguson, still without Ryan Giggs, said: "They're both very good footballers. I just think they have just got to get used to our game.
"They understand that all right but the most important thing is that they have the ability to perform and do well on a stage like Old Trafford and at the highest level.
"Karel showed some nice touches in the friendly against Inter Milan last week and Jordi could quite easily have had a hat-trick against Wimbledon."
Everton, though, were boosted by the way they blew Newcastle out of the picture on Saturday, and Joe Royle will be looking to Duncan Ferguson and former United favourite Andrei Kanchelskis to undermine the champions as they did Newcastle.
Royle is without skipper Dave Watson, who damaged medial ligaments against the Tynesiders, with Craig Short partnering David Unsworth in the middle of the back four.
A towering header by Ferguson beat United at Goodison two seasons ago, and with the Scotland manager, Craig Brown, due at Old Trafford before finalising his squad for next week's World Cup qualifier in Austria, the giant striker will be looking to repeat the dose.
Certainly Everton's performance at the weekend has raised the belief in the Merseysiders' camp, as John Ebbrell, who along with midfield partner Joe Parkinson will provide a combative test for Butt and Beckham, admitted.
"I thought we played really well in the first half on Saturday, and looked comfortable in the second, and it was just the sort of start to the season we wanted," said the former England under-21 man.
"The way we played on Saturday has given us a massive boost. Now we've already got a win it means we won't be under any pressure at Old Trafford. We know we can win there if we play as well as we did against Newcastle."
While United and Everton are both aiming to build on their brilliant starts, the sides they beat so comprehensively on Saturday have wounded pride to restore.
Keegan's judgement in splashing out so much for Alan Shearer without spending a penny on plugging the alarming leaks in his defence has been called into question after the Charity Shield and Goodison Park maulings.
Colombian Faustino Asprilla is back from suspension for Newcastle, and the Magpies' manager confirmed the pounds 7m South American would play, although he did not indicate who would be left out.
Keith Gillespie, who made way after Asprilla's arrival from Parma last season, could be the odd man out again, assuming that Shearer and Les Ferdinand again start together.
More worrying than his side's display up front was the shoddiness they demonstrated as Ferguson's aerial threat severely disturbed their composure on Saturday.