For the first time in his career, Jose Mourinho will step through the tunnel at Stamford Bridge as manager of Manchester United.

The twice-former Chelsea boss returns to his familiar stomping ground on Sunday for the first time since being fired in December 2015, and it is likely his reception will be frostier than he is used to.

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Not that Mourinho will mind. He will revel in it, though his candor with reporters in the buildup to the match has been business-first, as usual. Mourinho is a man who has courted controversy throughout his career, but he has chosen his words carefully this week.

“I knew that, working in England and staying in the Premier League, sooner or later I had to play against Chelsea and go to Stamford Bridge,” Mourinho said, as quoted by The Telegraph. “The computer has decided it is to go now. And here we go.”

Here we go, indeed.

Mourinho returns to his old home for just the second time as a former manager. He took his seat on the away bench in March 2010 with Inter, when he pocketed a comfortable 1-0 win on his path to an eventual Champions League title.

Before that match, Mourinho joked that he was “always lucky at the Bridge” and was greeted by the Blues faithful with open arms and banners praising his name. And, if anyone was going to oust Chelsea from the tournament, it might as well be Mourinho, the man who delivered the Blues glory in 2004 and 2005.

It was hard not to feel happy for Mourinho. The perception among Chelsea supporters then was that Mourinho was the victim of Roman Abramovich’s desperation, let go for a blip of poor results in September of the 2007-08 season but with rumours of infighting and discontent between the two permeating throughout.

Perhaps it was a lack of transfer funds or Abramovich’s insistence on the attempted revival of an aging Andriy Shevchenko that soured the relationship between the two. But, even now, after twice being fired, Mourinho harbours no ill will towards Abramovich.

Not that they’re chums, either.

“He was never my friend,” Mourinho said of the Chelsea owner on Friday, as quoted by The Independent. “We always had the relationship of owner-manager. Very respectful relationship. We were never friends. We were never close to each other. So, no. He is just a person that I keep very respected …”

It’s not hard to believe, since Abramovich gave Mourinho a second chance in the first place. His return to Chelsea was celebrated raucously and Mourinho looked happier than he did in Spain, where his reputation had taken something of a hit with Real Madrid.

At Chelsea, Mourinho was reminded of the comforts of a city full of support (from the blue-clad portions of London, at least) and a Premier League title in his second season renewed celebrations with a warm touch of nostalgia.

It would not last long.

In Spain, Mourinho was marked with “third season syndrome” as mutiny marked the end of his time at Real Madrid. His third year with Chelsea ended in disaster, too, as a 4-9-3 start to the 2015-16 season saw the Premier League champion slip to mid-table. In December 2015, Mourinho was fired.

This period of time did more to harm Mourinho than it did to change Chelsea. The same core players – Eden Hazard, Diego Costa, Willian, Cesc Fabregas, and Gary Cahill – remain in place. But the magic of Mourinho has been lost. His luster has faded. Even his perfect home record was broken by Sunderland.

The circumstances of Mourinho’s second exit from Chelsea has ruined his image of infallibility. The Portuguese tactician has said and done many things other managers might not say or do, but it was Mourinho’s ability to get results that made his word choices passable, made his decisions palatable.

Benching John Terry and blaming officials could be forgotten – if not entirely forgiven – if Chelsea kept winning, if Mourinho’s faults were not exposed.

Now surrounded by more charismatic men like Jurgen Klopp or more tactically savvy bosses like Pep Guardiola – and, arguably, a bit of both in Antonio Conte – Mourinho does not cut the same sort of hallowed figure as he once did.

It’s why his return to Stamford Bridge this time around isn’t floated with the same sort of careless whimsy expressed through the puffed-chest pride of competition. This is all business.

And this time, Mourinho is the enemy.