There was a popular joke that did the rounds throughout the final week of the World Cup.
"What's that scrabbling sound?"
"It's PSG's owners trying to find the receipt for David Luiz."
After a Titanic-like captaincy of a 7-1 defeat to Germany, Luiz's tears in a clown's wig in Belo Horizonte recalled that PSG just spent £50 million on him. Much mirth ensued, while Chelsea fans exhaled in satisfied relief at getting the deal done before the tournament.
On re-arrival at Chelsea a year ago, one of Jose Mourinho's first media leaks signalled a desire to cash in Luiz, as well as Juan Mata. He has his wish, and the World Cup made it look like he had pulled off the deal of the century.
However, the month in Brazil has given Mourinho plenty to deal with when his players return to the Cobham training ground and for their short series of preparation matches against European opposition.
A propensity to make such mistakes was the reason Luiz was rarely trusted at centre-half and grudgingly played as a midfield anchor. Now, Luiz is someone else's expensive problem, and the money hauled in for him helped pay for Cesc Fabregas, Diego Costa and Kurt Zouma, with the hope that the French defender is far less flighty than his Brazilian predecessor.
That Fabregas and Costa suffered in Spain's disastrous defence of the title may have slightly muffled the impact of those deals, though Mourinho will be glad they will get an almost full summer's rest.
Spain's fall will have brought him undoubted enjoyment in other regards. Iker Casillas and Sergio Ramos were leaders in the revolt that deposed him from Real Madrid; both led the list of culprits in that 5-1 opening defeat by the Dutch.
Other Mourinho foes took serious falls too.
He has often had a testy relationship with Luiz Felipe Scolari, who tried and failed to succeed him at Stamford Bridge. Lionel Messi, to whom Mourinho could only rarely find a solution, stopped short of achieving true greatness on a night when Andre Schuerrle, a Chelsea charge who is the willing type the manager likes, supplied the assist for the winner in the final.
Having a player hit such heights might be a boon to Mourinho's Chelsea, though he could also be glad that not too many of his players were involved in the showpiece. Players who win World Cups have not always gone on to enjoy successful Premier League campaigns in the following season.
France '98 winners Patrick Vieira and Emmanuel Petit ended the 1998-99 season potless at Arsenal, while Gilberto Silva struggled in the 2002-03 campaign for the same club. Spain's 2010 winners featured Fabregas and Fernando Torres, who both endured hugely disappointing campaigns in 2010-11.
Oscar, having shone in the opening match with Croatia, shrank into a shell he too often retreated to last season. Willian, who Mourinho last season converted from luxury player to power outlet, was one of the Brazilians who struggled to provide an alternative source of creativity to Neymar. Ramires' failure to impose himself on a malfunctioning midfield with anything other than some reckless tacking was another disappointment.
Costa, freshly arrived, was castigated for his failure to add a fresh dimension to Spain, while Cesar Azpilicueta was part of a defence picked apart by the Netherlands and Chile. Mourinho's sole English participant, Gary Cahill, had a yet more horrendous tournament, with his slips against Uruguay proving particularly costly. Conversely, John Terry's reputation grew anew through absence.
Eden Hazard, meanwhile, was part of a Belgium team that reached expectations, yet he played a disturbingly low-key role.
In February, Mourinho was suggesting that Hazard could reach the level of Messi and Cristiano Ronaldo, but he hugely under-performed both in Brazil, even allowing for their suffering significant disappointments.
Perhaps John Obi Mikel, a solid citizen in Nigeria's successful reaching of the last 16, was - behind Schuerrle - Chelsea's greatest success at the World Cup.
Now, in a season that must end with serious silverware after last season's failings, Mourinho must harness those experiences and put the World Cup behind him and Chelsea. He must achieve far more than getting a good price for David Luiz.
This article originally appeared on ESPNFC.com