Alvaro Negredo is set to miss out on Champions League football this season as City are are only able to name 16 overseas players to comply with Uefa regulations.
The Spaniard is out with a metatarsal injury at the moment and isn't expected back until the end of the year so will miss the majority of the Champions League group stages anyway.
Nastasic will also miss out on Champions League football at the Etihad Stadium this season, with Pellegrini expecting him to leave before the end of this summer's transfer window. Micah Richards and Scott Sinclair are also expected to leave City this summer and as such will not be in contention for Pellegrini's European squad.