There has been a seismic shift at Paris Saint-Germain. Where once the plan was to build a dynasty with Neymar as the centrepiece, the reality this summer is very different.To sell Neymar – either back to Barcelona or on to Real Madrid – was once unthinkable in the eyes of club president Nasser Al-Khelaifi. Now, it seems inevitable.Too much appears to have passed between Neymar and PSG; his time in the French capital – despite two Ligue 1 titles and a host of individual trinkets – has been a washout. Article continues below Editors’ Picks What is Manchester United’s ownership situation and how would Kevin Glazer’s sale of shares affect the club? Ox-rated! Dream night in Genk for Liverpool ace after injury nightmare Messi a man for all Champions League seasons – but will this really be Barcelona’s? Are Chelsea this season’s Ajax? Super-subs Batshuayi & Pulisic show Blues can dare to dream He never became that transformative figure the club so desperately required to take the next step.And now the club will no longer indulge him; the message being if you don’t want to be here, then leave.From his seeming indifference to middling league games to his chronic injury trouble – which put paid to both his Champions League campaigns in PSG colours at the last-16 stage – something always got in the way, preventing Neymar from becoming the undisputed hero in the eyes of PSG supporters.And their first home game of the Ligue 1 season – last week against Nimes – brought with it a shocking spectacle. PSG ultras carried banners in the stands and sang songs severely criticising Neymar, labelling him a mercenary and demanding his immediate dismissal from the squad.The message was that his heart was never in it, something that became all the more apparent when he recently labelled the Remontada – Barcelona’s stirring Champions League comeback against PSG in which Neymar was the protagonist – as one of the best moments of his career. That was taken as the ultimate display of disrespect for the club which pay him – handsomely – but one which he still cannot bring himself to love.Neymar has absented himself from humdrum matches with minor injuries and was reported AWOL this summer having failed to return from Brazil following yet another foot injury.He punched a fan after Rennes beat them in the cup final at the end of the season, and has got himself into trouble for messages sent on his Instagram account following PSG’s elimination from the Champions League by Manchester United.From a Ballon d’Or winner-in-waiting, Neymar now conjures trouble, more perhaps than it’s worth. And the question Real Madrid and Barcelona might well find themselves asking right now is whether or not Neymar is merely in a slump of his own making or is genuinely on the decline.He has been usurped by Kylian Mbappe – the local boy champion – who ended last season demanding more responsibility at PSG or else he would go and find it elsewhere.PSG are thought to be particularly spooked by the idea of Mbappe decamping for Manchester City, whose manager Pep Guardiola is a long-time admirer.Mbappe is a player PSG should build around for the decade to come and will be in line for a substantial pay-rise once Neymar leaves.On the surface, it looks similar to the situation Guardiola had in his in-tray when taking the Barcelona job in 2008, involving Ronaldinho and Lionel Messi.Ronaldinho had helped Barcelona reclaim their perch as one of the best teams on the continent having joined in 2003 from PSG.Under Frank Rijkaard, he had led Barca out of a six-year trophy drought and to two Liga titles, the 2006 Champions League and had secured the Ballon d’Or for good measure. He was – for a time – the best player the game had ever seen.But Ronaldinho – even though he was only 28 – was widely seen to be on the wane. His powers were diminishing, as the late nights and his own inimitable easy-going lifestyle clashed head-on with the demands of life as an elite sportsman.And, crucially, Barca also had Messi coming to prominence. While the two were and remain close friends, there was only going to be space for one of them as the fulcrum of Guardiola’s new-look Barca team.Ronaldinho helped nurture Messi to greatness and revealed to all and sundry that the little Argentine would surpass him as a player.And so he passed the baton to Messi, departing for AC Milan. He would never again achieve the heights he hit at Barca and wound down his career with only intermittent flickers of greatness from there on out.Messi, of course, has gone on to achieve countless honours, the best player Barcelona has ever seen and, arguably, the best player ever full stop.PSG find themselves at a similar crossroads; with the option to get rid of their landmark Brazilian superstar and leave control of the team at the feet of their promising young steed.The big difference? Neymar has got nowhere near Ronaldinho’s level, in terms of influence, legacy or trophies. No Ballon d’Or, no Champions League, nothing, in fact, out of the ordinary.And he will go not with affection from PSG fans but with a sense of what could have been.