The Sun says the Algerian ace went AWOL after a deadline day switch to the Etihad broke down when the Foxes rejected a £65m plus player offer.
The 26-year-old has even been offered help by the PFA after becoming depressed over the failed move to City.
But Pep Guardiola is aiming to make another attempt at signing him when the summer window opens, to bolster his squad.
City hope Leicester will be open to selling him when they have more time to find a suitable replacement.
And Etihad chiefs are planning further talks when the Foxes travel to the Premier League leaders this coming weekend.