Hostility between the two sides reached new levels as Qatar-backed PSG took Neymar from under the nose of Barcelona, in doing so acquiring their natural heir to the throne of Messi.
The transfer could be finalised as early as next Monday but questions will surely be asked regarding the Financial Fair Play rules, as the combined fee of Neymar and Mbappe would surpass £360 million.
Anything other than a spectacular debut showing from Neymar and the criticism will begin in earnest.
In the tiny Brittany town of Guingamp, with a population of around 7,000, tickets for the match have been changing hands for a king's ransom as the Stade du Rouduorou has a capacity of just over 17,000.
PSG Manager Unai Emery would not confirm the new No. 10 would play, however, although he noted on Friday (via the BBC) that Neymar was "physically ready to start".
With worldwide transfer documents finally received by the French Football Federation from their Spanish counterparts, the world's most expensive footballer is primed for a first appearance with his new team.
He said, "Everyone in the world will be watching, so it's also a really good platform for us as players that are unknown".
In Irving's case, we have yet to see what will lie ahead for him.
Lionel Messi's reported €300million release clause may come under threat if Paris Saint-Germain were willing to fork out €222m for Neymar. "Where we want to go and where this should stop", Klopp added.
Premier League title hopefuls Manchester City do remain keen on securing a deal for the 18-year-old, but they are unwilling to pay his asking price at present.
And who's gunning for Neymar's debut jersey at the end of the game?
A Paris source said a bid of around €45 million had been tabled by PSG once Henrique arrived - but he was then told he could not join them.