There will be some familiar faces awaiting José Mourinho when, as expected, the Special One – newly liberated by Real Madrid – secures his second coming at Stamford Bridge. Five senior players remain on the books from his glittering first spell in charge at Chelsea and a sixth, Michael Essien, will accompany him back from Madrid. Some of the medical and performance staff, whether analysts or masseurs, linger on. Even Gary Straker, the steward-cum-Italian interpreter turned player liaison officer and one of the great survivors at the club, is still on the day to day scene down at Cobham.

Mourinho will presumably relish renewing old acquaintances, yet it is how he copes with the aspects of the job that may feel rather alien that will determine how long this reconciliation endures. This is a very different Chelsea to the one he left so abruptly, and acrimoniously, in the autumn of 2007 when his relationship with the owner, Roman Abramovich, appeared fractured beyond repair. His original brief had centred upon winning a first Premier League title in half a century, a task achieved at the first attempt, and an inaugural European Cup. That was only secured in his absence, albeit largely with his team. Regardless, he had overseen a revolution featuring a blend of charisma and siege mentality that was ideal at a club muscling its way into the establishment. These days Chelsea talk more of evolution. Therein lies the anomaly of turning to a manager whose appointment tends to guarantee both trophies and, ultimately, a messy divorce.

The Portuguese will arrive mid-project. As Rafael Benítez has been quick to point out over recent weeks, this is a team in transition, a side that includes the first wave of younger talent recruited at significant expense. Juan Mata, Eden Hazard, Oscar, and even César Azpilicueta, Victor Moses and David Luiz, were bought to fit into a framework that aped Barcelona's quick-step, the same ideal Mourinho has spent the last three years attempting to usurp.

The club's extensive recruitment and scouting department, overseen by the technical director, Michael Emenalo, is apparently working towards a long-term strategy, even if there has been an imbalance in the senior squad assembled so far. The hope is that Mourinho buys into the overall vision and does not merely set back what progress has been made. Chelsea spent about £90m during his first summer in south-west London, an outlay that would not feel outlandish if repeated nine years on. But, back then, that bought eight players who arguably became integral to his first-choice line-up. Emenalo would suggest the spine is already in place this time around, and that no radical overhaul is required. Indeed, the new manager must also assess the entire squad of youngsters loaned out last season – from Romelu Lukaku to Jeffrey Bruma, Patrick van Aanholt to Josh McEachran – before determining the make-up of his side.

Working with Emenalo will be key. Since joining as a scout under Avram Grant a month after Mourinho's exit, the former Nigeria and Notts County defender has made himself a powerful figure, close to the owner and hugely influential within the set-up, whether earmarking potential signings or reporting back on the current staff. The 47-year-old's rise may have appeared rapid and unexpected, but he has arguably become the owner's eyes and ears down at the training ground, a man whose input is valued. Emenalo is here to stay. Mourinho will have to work with him in a way he would never have accepted with Grant, who had been imposed upon him as a director of football in the summer of 2007.

Indeed, he will have to accept the entire infrastructure of the club this time around, from the chairman, Bruce Buck, to the chief executive, Ron Gourlay. The schism that occurred with his employers six years ago had been born of a perception within the hierarchy that Mourinho felt, and acted, as if he owned the club. The parting of the ways represented the owner reasserting control. The problem is that Abramovich has lurched from manager to interim in the years since and never stumbled upon a candidate capable of amassing the trophies the Portuguese secured in a little over three seasons at the helm. Mourinho may be volatile, a ticking time-bomb off the pitch, but he generally succeeds on it.

This time he must also contend with expectation. He had arrived a Uefa Cup and Champions League winner in 2004, but was still a relative unknown. Chelsea's supporters at the time felt a certain loyalty to the deposed Claudio Ranieri, but were blown away by the sheer brilliance of the new manager: whether he was defending the club in public, riling opponents so brazenly, or transforming matches with tactical tweaks that felt bold and innovative. He was a breath of fresh air. This time round, the fans – so disenchanted by the treatment of Roberto Di Matteo and the willingness to turn to Benítez as a stop-gap replacement – expect their idol to have a similar effect again, completing the team's transition in a blaze of glory reminiscent of those title successes in 2005 and 2006. Yet he will arrive at a club that has secured European trophies in the past two seasons, the margins for progress so much tighter than they were. Mourinho will be welcomed by those in the stands and will savour the task ahead, but this feels like a very different challenge.