The cat was finally let out of the bag on soccer's worst-kept secret when the 2012 European champions ended months of media speculation to announce on Monday that their former coach was coming back for a second stint in charge.
The Chelsea faithful were in mourning when Mourinho left the London club under a cloud in 2007 and have been pining for his return ever since.
Coaches at Stamford Bridge have come and gone at a dizzying rate in the last six years - the most recent being Rafael Benitez.
He did a good job in an interim capacity last season after the sacking of Champions League-winning coach Roberto Di Matteo but the Spaniard was never going to be accepted by the fans after making some barbed comments about the club during his time at Liverpool.
Chelsea supporters never forgot the way Mourinho, the self-proclaimed 'Special One', took the team by the scruff of the neck in his first season to land their first top-flight championship for 50 years in 2004-05.
Not content with that, the Londoners then romped to a record-breaking title triumph in his second campaign.
Mourinho's great strength was the way he galvanised a squad choc-full of strong characters such as John Terry, Frank Lampard, Didier Drogba, Hernan Crespo, Arjen Robben and Michael Ballack into a powerful unit where the team ethos was the be-all and end-all.
"Tactically he's fantastic, very astute," the club's record goal-scorer Lampard told Talksport radio. "As a team he sets you up brilliantly but what he does is he gets the best out of players.
"He gets this togetherness that I'd never known until he came to the club and I haven't seen it again since. He might rub people up the wrong way but as a manager he's brilliant with individuals and I think he's brilliant with the press.
"I know it creates a storm but he does protect his players."
The remarkable money-no-object transfer policy that took football by storm when Russian billionaire Roman Abramovich bought Chelsea in 2003 led to much envy from fans of other clubs up and down the country.
The cunning Mourinho used that to his advantage when he joined as he created something of a siege mentality within his group of highly-paid players, adopting a 'they don't like us, we don't care' type of response.
For England midfielder Lampard, the outspoken Portuguese was a welcome breath of fresh air.
"He has a presence and an aura and a way with people," said Chelsea's vice-captain. "He galvanises people.
"His own self-confidence reflects back on his teams and he did that to me personally."
Mourinho's first two years at Chelsea went like clockwork but his relationship with Abramovich then seemed to sour and it came as no real surprise when they parted company.
The coach's media utterances had begun to grate on the Russian and on many others in the game - but Lampard said it never irritated him.
"I wasn't fed up with it," said the former West Ham United player. "He made me believe I was better than I was at the time.
"I thought I was a decent player but he said to me 'listen, you can really get to the top' and he made me believe it. I tried to take it on and do it."
Last month Lampard bagged his 203rd goal for Chelsea as he eclipsed former striker Bobby Tambling as the club's all-time record scorer - a tremendous achievement for a midfielder.
Lampard has also had a brilliant international career, snapping up 29 goals in 97 appearances for England.
"For me Mourinho was the best. He brought my confidence to a level it had never been," he said.
- Sports & Recreation
- Frank Lampard