Despite welcoming Caballero to the club in the summer, Pellegrini has chosen to keep faith with Hart, but has suggested that he will rotate his goalkeepers just like every other position.
"Of course Willy Caballero can be in any team, he's a very good goalkeeper. In this moment I'm playing Joe Hart but he will have his opportunity soon," the Chilean told reporters
"Willy has a good career behind him. It's important to have competition in every position in the team, not just with Joe Hart and Willy Caballero.
"Replacing Joe Hart with Willy Caballero doesn't make a difference - just as [replacing] [Pablo] Zabaleta with [Bacary] Sagna or [Eliaquim] Mangala with [Martin] Demichelis or [Edin] Dzeko with [Sergio] Aguero, it's exactly the same."
Manchester City face Arsenal on Saturday afternoon.