PSG's defining summer with potential to lose Lionel Messi, Neymar AND Kylian Mbappe

'We want players who love the club, who love to fight, who love to win,' Nasser Al-Khelaifi told Le Parisien last year. 'And we want this mentality to spread throughout the club.'

And now, one year on, Paris Saint-Germain look like they mean it.

The appeal to land star names outside of their prime years has waned and has instead been replaced with an appetite to build from young and put faith into finding talent in a hotbed as rich as Paris.

Lionel Messi, 35, and Sergio Ramos, 37, have left; Mauro Icardi, 30, has come back from a loan spell with no chance of reintegration; one-time wonderkid Julian Draxler, now 29, is somehow still on their books six years after signing and now Kylian Mbappe, much as he did last summer, has put them over the barrel in regards to his future. Only this time, PSG appear unbothered to be held to ransom.

PSG have long found themselves mocked for the level of power afforded to players and it has ultimately proved their undoing, with a lack of unity and an effective team press their downfall in the Champions League.

What they were at least able to hold close is that Mbappe, who can make an argument to be the best player in world football right now, was in their ranks.

PSG went out of their way a year ago to convince Mbappe to stay in Paris and snub the admiring glances from Real Madrid.

Mbappe had ran his deal down and looked destined to head to Spain - only to perform a shock U-turn, penning a deal that was reportedly going to earn him £547m over three years (provided he took up the option it is now claimed he will not activate).

That meant that Mbappe was handed the biggest ever contract - which included a near £130m signing on bonus - for a sportsperson when he signed his new deal at PSG, and yet 12 months on he is again flirting with a move away.

And now PSG, according to French newspaper L'Equipe, feel a sense of 'betrayal' and are ready with an ultimatum: sign the extension or pack up and leave.

That right there is the revolution PSG are facing. A shift from ageing stars to talented young prospects.

A three-pronged approach of 'youth, with French nationality, and team-oriented' is what PSG sources have been cited as suggesting in local media.

Slovakian centre back Milan Skriniar is arriving on a free to replace Ramos, nine years his senior, while 22-year-olds Kang-in Lee and Manuel Ugarte, who PSG have fended off competition from Chelsea for, are among the first expected through the door.

Marco Asensio, 27, is another free signing PSG are expected to make this summer.

The difficulty facing PSG is how far - and how quickly - they take this rebuild.

A younger, less star-driven side can still win the Ligue 1 title - but that is not what Qatar Sports Investments (QSI) were targeting when they purchased the club on June 30, 2011.

That would be the Champions League and PSG find themselves stuck between wanting to remodel the whole house and wanting to keep various pieces of shiny furniture.

Neymar, the final Galactico from the famed front three, has been a piece PSG have flirted with selling for years now.

The Brazilian reportedly has admirers in Saudi Arabia, but with the 31-year-old on a monster contract that doesn't expire until 2025 there could well be a reluctance on behalf of the player to leave.

But if PSG are truly serious about a new philosophy 'based on the collective and not on individuals' then Neymar is not - and cannot - be a major player in the future.

One of the most damning indictments of PSG in their current guise was the unwillingness to press from the front. Messi, Mbappe and Neymar all wanted to attack, and not defend, and it was down to Mauricio Pochettino, and later Christophe Galtier, to silently curse the divide in responsibilities.

That is changing, or at least those are the noises coming from Paris.

Centre back, as well as Skriniar, a central midfielder, a winger and a striker are all on the shopping list, with L'Equipe naming the following as targets:

The other key factor here is that PSG are targeting a new coach, a younger coach, that fits this new 'project' in rebuilding. Specifically, that's Julian Nagelsmann.

Nagelsmann's appointment is reportedly imminent and while he has failed to this point in convincing Thierry Henry to be his No 2, establishing a key figure in his backroom team with a history, knowledge and presence in French football seems wise, particularly with PSG's interest in adding more and more Frenchmen to the dressing room.

Nagelsmann turned down Chelsea and Tottenham this summer and is said to have had 'positive talks' with PSG.

Whether Mbappe's bombshell announcement that he is not signing an extension at PSG will alter his thinking remains to be seen, but there is something to be said about being able to tear something down and build it back in your own image.

That is the challenge to PSG now: young, French and team-orientated.

It won't all come in one window and it won't all come cheap. PSG need to continue being successful and competitive but others have shown that players comfortable in their roles can be far greater than the sum of their parts - see Inter Milan in the Champions League final.

For possibly the first time since Qatari ownership took hold at PSG, they can see life after big names depart. What was once a terrifying prospect - not least commercially - has now turned itself into an opportunity.

That all starts this summer - with or without Mbappe.