Jose Mourinho moved a step closer to Manchester United and a Premier League return after his representatives held talks with the Old Trafford hierarchy as they line up a successor to Louis van Gaal.
Van Gaal is still in position and has a contract that ends in 2017 - but United's move for Mourinho increased the likelihood the Dutchman will leave at the end of the season, with 'The Special One' succeeding his old mentor.
No job offer has been made to Mourinho as United make their soundings out, but the man sacked by Chelsea in December, seven months after winning the title, now looks certain to be in opposition to old adversary Pep Guardiola when the Spaniard takes charge at arch-rivals Manchester City.
|Mourinho in the Premier League|
How would Man Utd fans feel about Mourinho?
Mourinho has always been a divisive figure throughout a combustible career, liberally sprinkled with controversy - and when it was suggested just days after he left Chelsea that he might be Old Trafford-bound, opinion was mixed.
Since then Van Gaal's stock has fallen even further among United's fans, with the prospect of Mourinho taking the reins becoming increasingly appetising.
Mourinho is the man who can rekindle the fight, defiance and colour in Manchester United after the drab flourishes applied to "The Theatre Of Dreams" by David Moyes and Van Gaal since Sir Alex Ferguson's retirement in 2013 after 26 years.
And Old Trafford's appetite for Mourinho's unique combination of abrasive self-confidence mixed with consistent success will have been sharpened by City's coup in luring Guardiola, the world's most celebrated coach, to the Etihad.
Put simply, post-Van Gaal, United fans will demand someone who can stand toe-to-toe with the iconic Guardiola, not just in fighting their corner, but in bringing success - Mourinho's track record makes him that man.
Chelsea's fans may have mixed emotions to see the manager they worshipped battling them on all fronts - but they will also accept it was not his decision to leave Stamford Bridge.
Could Mourinho light up the 'Theatre of Dreams'?
Mourinho's career has been characterised by success but his detractors would suggest it has come at a price that has put pragmatism before football that is pleasing on the eye - how would that sit at Old Trafford?
One of the main criticisms of Van Gaal is that £250m spent on new players has delivered a functional, joyless style that has dulled Old Trafford's senses, including a run of 11 home games without a first-half goal this season.
The shadow of the flamboyant, all-out attack of the Ferguson era has hung heavily over both Moyes and Van Gaal, and there will be pressure on Mourinho to alter his usual functional template.
He might argue, with plenty of justification, that any reservations about his methods are eased by the fact he is a virtual guarantee of trophies - something Old Trafford's traditionalists may accept as a price worth paying for the Mourinho ticket.
And is it a valid argument anyway?
When Chelsea won the title last season, their early season performances - inspired by summer acquisitions Diego Costa and Cesc Fabregas - were the perfect blend of exciting attack and defensive steel that is Mourinho's trademark.
Chelsea scored 73 league goals, 10 fewer than second-placed Manchester City, but two more than Arsenal - with Arsene Wenger's side often held up as the purists' delight.
And when Mourinho won his second title with Chelsea in 2005-06, they equalled the goal tally of runners-up Manchester United with 72, but only conceded 22 to Manchester United's 34.
Mourinho also gave the lie to the image with Real Madrid when they won La Liga in 2011-12. They scored the most league goals in a season with 121, had the best goal difference in a season of +89, the most points in a season at 100 - 87.72% of points they contested. He is not a one-trick pony.
Mourinho has observed Old Trafford for long enough to know what is required - and while his first priority is always to win, he is wise enough to know that a certain style is demanded.
Silverware will do for starters. And few managers are better at that.
Is Guardiola behind Mourinho move?
Manchester United are not the sort of club to be bounced into big appointments - but Guardiola's arrival at Manchester City will have concentrated minds fiercely.
It left them in the shadow of the so-called "Noisy Neighbours", whose recent growth has enabled them to secure the most coveted coaching name in world football - a man of such reputation he would have been welcomed with open arms by United fans.
It needed a response given the uncertainty surrounding Van Gaal's long-term future. The next manager, should Van Gaal go, needs to be a manager of iron will, character and a proven winner.
United surely cannot risk putting a rookie in the shape of Ryan Giggs - no full-time management experience and nothing to suggest he will succeed - against Guardiola.
Once Guardiola's arrival was confirmed by Manchester City, the chances of Mourinho arriving at Old Trafford rose instantly.
What next for Van Gaal?
Louis van Gaal has been in defiant mood in recent weeks, but he has been around long enough to know the credits are rolling, with United sounding out possible successors.
United would not be doing their duty if they ignored a succession plan, and Mourinho's availability and Van Gaal's struggles appear to have brought that forward.
The Dutchman, 64, was already working under a shroud of uncertainty and revelations that negotiations have been held with Mourinho's representatives will only make that darker - but he is a proud man and will not leave quietly.
Van Gaal still believes United can end the season with a trophy - but he will surely know the talks with Mourinho's people push him closer to the door.
And what next for Ryan Giggs?
Giggs has sat silently at the side of Moyes and Van Gaal since Ferguson left - would he be prepared to do it again should Mourinho arrive? And would it do him any good?
There is only so much managerial experience Giggs can pick up as a sidekick, even if Mourinho wants to introduce an "outsider" into the trusted backroom staff he takes everywhere with him, such as Rui Faria and Silvino Louro.
If Giggs is passed over as Van Gaal's successor then surely it is time for that member of the influential 'Class Of 92' to strike out on his own and prove his worth as a manager to make his case as a future United boss?
It would be time for Giggs to be more than a silent partner.
Ins and outs under Mourinho?
If Mourinho arrives, that will surely spell the end of any late and lingering hopes that Cristiano Ronaldo would return to Old Trafford.
The pair's relationship fractured totally at Real Madrid, so that can be forgotten - and even suggestions United might want to pay £65m for Everton's Romelu Lukaku may go on ice as Mourinho did not trust the striker at Chelsea and agreed to his £28m sale in summer 2014.
One Everton player who might be of interest to Mourinho is John Stones, who is expected to leave Goodison Park in the summer and was the subject of a £38m bid when he was Chelsea manager last summer.
Mourinho is also a long-term of admirer of Real Madrid's Gareth Bale, whom United have coveted for years, but he would not be alone there. Plus Real's outstanding young defender Raphael Varane might also be on his list.
It may be bad news for Juan Mata, a popular and influential figure at Old Trafford. He was, however, also popular and influential at Chelsea, but was not Mourinho's type and was willingly sold to United for £37.1m in January 2014.
Will Mourinho ditch the baggage?
Manchester United pride themselves on a certain style - and may well insist Mourinho ditches the confrontational approach that has brought so many bad headlines over the years.
Sir Bobby Charlton is not a decision-maker at Old Trafford, but the opinion of a man of such stature always carries weight and he may have pointed up areas of concern in an interview some years ago.
When Mourinho gouged at the eye of the late Tito Vilanova, then Barcelona's assistant coach, in the 2011 Spanish Super Cup, he said: "A United manager wouldn't do that."
He added: "He is a really good coach but that is as far as I would go, really. He pontificates too much for my liking. He is a good manager though."
History tells us, however, that Mourinho has always shown respect bordering on reverence for United - particularly when returning for Champions League games with Inter Milan and Real Madrid.
Was he preparing the ground and burnishing his image for his potential appointment? We may soon find out.