Tensions between the pair have worsened since PSG made Mbappe the highest-paid player in world football with a new three-year contract this summer.
It is claimed that Mbappe no longer wants Neymar in the PSG team, while the Brazilian "has been left astonished by the influence" the French striker has been given since signing his new deal at the Parc des Princes.
The report claims Mbappe would not have opposed the sale of Neymar in the summer transfer window, as PSG's de-facto sporting director Luis Campos looked to reshape the squad.
Despite reports linking Neymar with a summer move away from PSG, the 30-year-old – who has been with the French club since 2017 – remained for another season.
He is now reportedly convinced that Mbappe attempted to persuade PSG to sell him in the last window.
Earlier this season, tensions between the pair boiled over in a row over penalties in a match against Montpellier in August.
Mbappe had missed a penalty earlier in the match when PSG were awarded a second spot-kick.
Neymar appeared to refuse to allow Mbappe to take the second penalty, with the Brazilian instead stepping up to score.
Reports in France claimed the pair had to be separated after the match, which ended in a 5-2 win for PSG.
During the recent international break, neither player directly addressed the reports of their dressing room rift.
After Brazil's friendly against Ghana in Le Havre, Neymar refused to answer a question about Mbappe – storming out of the post-match interview area when his teammate's name was mentioned.
Mbappe, meanwhile, suggested he is happier playing for his national side than with PSG and Neymar.
"I have a lot more freedom here [with France]. In Paris, it's different, there isn't that. I am asked to do the pivot, it is different," Mbappe said after France's win over Austria.
L'Equipe claim the relationship between Mbappe and Neymar has deteriorated to such an extent that Lionel Messi has been forced to act as a mediator between the pair to keep PSG's season on track.
Despite the reported dressing room issues, PSG have made a strong start to the campaign and are currently two points clear of Marseille at the top of Ligue 1.
Christophe Galtier's side next face Nice on Saturday before travelling to Portugal to take on Benfica in the Champions League on Wednesday.
Featured Image Credit: Alamy
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