Nasri was considered to be at fault for Manchester United's late winner at the Etihad Stadium on 9 December, with a Robin van Persie free-kick deflecting off the Frenchman and past Joe Hart.
City boss Roberto Mancini was openly critical of Nasri in the aftermath of the game, with it felt that the former Arsenal man could have done more to block the winning strike.
He was selected for a victory over Newcastle the following week, but is currently sidelined with a groin injury which looks set to keep him out until the New Year.
It remains to be seen whether Nasri will be drafted straight back into Mancini's plans when fully fit, with his representative revealing that the 25-year-old still feels hard done by.
Jean-Pierre Bernes said: "He's a bit isolated, internally, even though he is a solid man.
"I think that, effectively, he has feelings of inner suffering with regards to that incident (against United) because it was not fair.
"I think you have to be fair in life, you shouldn't be excessive."