How will PSG get around FFP rules?
After spending 380 million euros ($450.66m) to secure the services of Neymar and Kylian Mbappe, Paris Saint-Germain's next task is to make sure they don't break UEFA's Financial Fair Play (FFP) rules.
European football's governing body opened an investigation into PSG's lavish spending on Friday, having previously sanctioned the club in 2014 for FFP violations.
PSG, who made Neymar and Mbappe the two most expensive players of all-time, responded by saying they expect a "rise of 20 to 40 percent" in revenues from "international income, sponsoring, merchandising, ticket sales, TV rights, sporting results and summer and winter tours".
The club need to increase their estimated annual turnover of 520 million euros by somewhere between 105 and 210 million to comply with FFP, and there are plenty of ways they can do it.
FFP rules dictate that a club cannot make an annual loss of more than 30 million euros, and an obvious way for PSG to avoid this will be to ship off some dead wood from their squad in the January transfer window.
After their summer acquisitions, there are some highly-valued players who coach Unai Emery will probably find surplus to requirements.
The website Transfermarkt values PSG's squad at more than 520 million euros, but as the signings of Neymar and Mbappe show, that is almost certainly an underestimate.
Forwards Javier Pastore, signed in 2011 for 42m euros, Lucas Moura (40m euros) and Angel Di Maria (63m euros) are all unlikely to have a regular starting place.
Neymar and Mbappe, 18, are both all but certain to start the big games alongside Edinson Cavani, and with Julian Draxler next in line, PSG could easily recoup some cash by selling Pastore, Lucas and Di Maria.
BIGGER SPONSORSHIP DEALS
One of the biggest reasons for shelling out a world record 222 million euros on Neymar was because of the Brazilian's marketability.
PSG president Nasser al-Khelaifi said after the 25-year-old's move that he would be worth 450 million euros "soon".
PSG's current deals with kit manufacturer Nike and shirt sponsor Emirates airlines (an estimated annual 40m euros) are far from the dizzying heights enjoyed by the likes of Barcelona and Real Madrid.
Barcelona receive at least 150 million euros annually from Nike for the privilege of making their jerseys, while English giants Manchester United are paid 67 million euros a year by Chevrolet in a shirt-sponsorship deal.
The scope is clearly there for PSG to find a far more financially-attractive deal after Neymar's signing, which could potentially wipe out any FFP fears in one swoop.
SUCCESS ON THE PITCH
Qatar Sports Investments have always wanted to win the Champions League since taking over PSG, and one way to avoid FFP sanctions would be to achieve just that.
With TV rights for Europe's premier competition at an all-time high, reaching the final for the first time could pay out more than 100 million euros.
Retaking the Ligue 1 title from Monaco would also help, while the French top flight's international TV rights will have gone up in value after the Neymar signing.
The French league's (LFP) international rights were sold for just 80 million euros annually for 2018-2024, compared to 700m euros for La Liga and one billion euros for the Premier League.
"At a domestic level, the LFP is even more likely to reach or exceed an annual figure of one billion euros," according to French economist Jean-Pascal Gayant.
PSG have plenty of cards to play, and if the 145 million-euro fee for Mbappe (before add-ons) is judged to come under expenditure for next season after his season-long loan deal from Monaco, then they might not have too much to worry about anyway.