Last season's top scorer has been out since suffering a knee injury in the season-opening defeat of Southampton at the Etihad Stadium last month.
City had been hopeful the 24-year-old Argentine could return by the middle of September and manager Roberto Mancini feels he has made good progress since resuming training earlier this week.
Mancini said: "We try this morning with Sergio and after training we decide. He is getting better - maybe."
Fellow forward Mario Balotelli is cleared to play after undergoing laser eye surgery during the international break.
The Italian had had difficulty wearing his contact lenses after being affected by conjunctivitis.
Mancini said: "Mario is okay - Mario now sees everything."
England midfielder Gareth Barry is close to returning after overcoming the abdominal problem that kept him out of Euro 2012 but Micah Richards remains out with an ankle injury.
Mancini reports no new problems concerning the players returning from international duty.
The boss now has the chance to work with his full squad for the first time since making five signings on last month's transfer deadline day.
Of those, Scott Sinclair, Maicon, Javi Garcia and Matija Nastasic could be in contention to feature at some stage at the Britannia Stadium.
Mancini said: "We don't have any players with (new) injuries, we are all okay.
"Always is the wrong time for the international break but we have a lot of players."