Manuel Pellegrini has told goalkeeper Joe Hart he can expect to miss games this season as the Manchester City boss manages his squad through four competitions.
Hart lost his place last autumn after a series of errors and was replaced by Costel Pantilimon before returning to enjoy a strong second-half of the season as City won the Premier League title.
But the 27-year-old was partially at fault for Mame Biram Diouf's breakaway winner in Stoke's shock victory at Eastlands a fortnight ago, prompting questions about the possibility of new signing Willy Caballero, who played under Pellegrini at Malaga, making his debut soon.
Pellegrini said: "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.
"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) Zabaleta with Sagna or Mangala with Demichelis or Dzeko with Aguero, it's exactly the same.
"We need a squad if we want to win something."
However, Pellegrini assured Hart he will not be dropped on the basis of any isolated errors.
"I am not waiting for Joe Hart to make a mistake to change him for Willy Caballero," he added.
"Willy Caballero and Joe Hart know that I'm not waiting for Joe to make a first mistake and take out Joe Hart. Maybe last year Joe didn't start very well but he finished very well."
City face a tough week with a trip to Arsenal on Saturday followed by a midweek Champions League game at Bayern Munich before a visit from Chelsea, but Pellegrini would not be drawn on whether it would mark the start of any goalkeeper rotation.
"I really don't know, we'll see game by game. We'll play against Arsenal and one hour and 15 minutes before kick-off you will know which goalkeeper starts."