Why not?
Because a) They won't have played together in two weeks, so two games in 4 days won't exactly be a stretch for them. and b) Their CL teams this season haven't been their 'strongest' (Aguero often coming off the bench etc.).
They'll go full strength IMO.
Most of them will be off on international duty though so they'll still be playing. They've rested players a few times before a CL game already this season and the Napoli game is their biggest game yet. You cannot rule it out.