PSG confirmed this week that Rabiot will no longer represent the club in the first XI under manager Thomas Tuchel after 'disrespecting' the Ligue 1 champions by refusing to sign a new contract.
In response, the club's fans unveiled a banner during a league cup game on Tuesday stating: "We do not need you, Rabiot.'
The French giants claimed the lack of loyalty of developing the academy graduate to move on without compensation to one of their European rivals is due to the illegal 'tapping up' of the France international.
According to reports, Barca initiated talks with Rabiot's agent over a potential Bosman free transfer, which could see him sign a contract with the LaLiga giants next month before departing at the end of the season.
This has clearly rattled PSG, who've held a rocky relationship with the Spanish side since the acrimonious Neymar world-record move from Catalonia to Paris.
"It always surprises us that clubs don't follow the rules," said Sporting director Antero Henrique of Barcelona's conduct surrounding Rabiot, more specifically accusing the Nou Camp club of agreeing a contract with the player outside the permitted six-month window for Bosman transfers and without permission from the Parisians.
Rabiot's mother and agent, Veronique, announced this week that the player's decision to leave was "firm and definitive" and was a case of freedom to choose rather than money.
But Henrique bristled at the latest revelations in a transfer saga that PSG just want to go away.
"She said that we received an offer this summer and that's true, we received it on August 29th at 8pm, just before the window closed. That's telling, it shows that Barcelona had reached an agreement with Rabiot before coming to speak to us. The proposal from Barca was ridiculous and the club was very surprised that the offer was so low.
"It was a disrespectful proposal for a player of the top level like Rabiot. I insist, it is not possible to arrive at an agreement for a player like him in 24 hours. That's why it is clear that they already had an agreement."