Mauricio Pochettino is back in the Premier League with the tough task of putting the pieces back together after Chelsea's disastrous first season under their new ownership.
The Argentine will take charge of a club that finished 12th in the Premier League despite an eye-watering outlay of more than £550 million ($678 million) on new players under Todd Boehly's consortium.
Pochettino made his name in management by making the most of meager resources at Espanyol, Southampton and particularly during a five-year stint at Tottenham.
Eighteen months at Paris Saint-Germain delivered the first silverware of the 51-year-old's career -- the Ligue 1 title and French Cup -- but he never appeared comfortable managing the egos of a star-studded squad before leaving in July 2022.
Pochettino's man-management skills will face a severe examination at Stamford Bridge as he tries to succeed where three managers have already failed under the new regime.
Thomas Tuchel, who led Chelsea to Champions League glory in 2021, was unceremoniously sacked by co-owners Boehly and Behdad Eghbali, of private equity firm Clearlake Capital, just seven games into this season.
At the time Chelsea sat sixth in the Premier League and few could have foreseen the calamity that would follow the German's departure.
Graham Potter lasted less than seven months at Stamford Bridge, even though Chelsea paid more than £20 million to snatch the Englishman from Brighton.
Even worse was to follow as club great Frank Lampard returned as interim boss only to oversee six successive defeats in his first six matches.
Bloated squad. All three bosses have faced the challenge of hands-on owners and a bloated squad.
Experienced defender Thiago Silva confirmed last month that the club had to extend the dressing room to accommodate a group of more than 30 players.
A major clear-out is needed at the end of the season to give Pochettino a more manageable squad to work with and instill a team spirit that has been sorely lacking.
Chelsea's huge spending over the past 12 months may mean he has limited room for maneuver in the transfer market.
The Argentine faced a similar challenge at Tottenham, when the club punched above its weight to finish in the top four of the Premier League four times under his leadership.
The Blues' spending is under scrutiny due to financial fair play controls but much of their outlay was with one eye on the future.
Wesley Fofana, Benoit Badiashile, Enzo Fernandez, Mykhailo Mudryk, Carney Chukwuemeka, Noni Madueke, David Datro Fofana, Malo Gusto and Andrey Santos are all 22 or younger.
Chelsea have been ridiculed for putting some of those players on eight-year contracts, but the club's ownership are betting on Pochettino's record with young talent to prove them right.
He produced impressive results at Tottenham, helping turn young home-grown talents such as Harry Kane and Dele Alli into household names on a budget.
"I can't speak highly enough of him. He's a fantastic manager, a fantastic man," said England captain Kane, during their time together at Spurs.
"You just want to perform for him, work hard for him, win for him. He's very passionate. You can tell sometimes he wants to be out there himself, putting in tackles, running about. "You respond to that. On nights like that, big occasions, you just want to do him justice."
Before appointing Pochettino, Spurs had only finished in the top four of English top-flight twice in 24 years.
He also inspired a run to the club's first-ever Champions League final in 2019 and Tottenham's struggles since his departure have led to a clamor from fans for his return.
Pochettino's reputation appears to be untarnished by his indifferent spell at PSG, given the French giants' struggles on and off the field this season.
Should he turn Chelsea's motley crew back into Premier League contenders, his status as one of the world's leading managers will be restored.
© Agence France-Presse