Manchester City manager Manuel Pellegrini has warned Joe Hart he has no room for error if he wants to remain the team's first-choice goalkeeper.
Hart suffered a dip in form last season which saw him replaced in goal for a month by Costel Pantilimon before the England international re-established himself as Pellegrini's regular number one.
City allowed Pantilimon to depart the club in June when his contract expired and the Romanian subsequently joined Sunderland on a free transfer.
But Pellegrini replaced him in the City squad with Argentine Willy Caballero, who he signed from former club Malaga during the close season.
The Chilean indicated Caballero, 32, will be better placed to challenge Hart for a starting position in the forthcoming campaign.
And Pellegrini may elect to give Caballero an early chance to impress when the Premier League champions face Arsenal in the Community Shield at Wembley on Sunday.
"I have two No. 1 goalkeepers," Pellegrini said. "Willy is a very good goalkeeper, I know him from Malaga. I think he is very happy here. That is why I say we have a stronger squad than last year.
"I will make the decision who will start against Arsenal, not only the goalkeeper, the whole team.
"I am sure Willy will be very important for us but I also continue thinking we have the best goalkeeper in England in Joe Hart.
"Top teams need two players for each position because we have to play so many games during the year."
None of the City players who arrived back from their post-World Cup holidays on Monday, including Sergio Aguero and Vincent Kompany, will be involved in the curtain raiser to the new season against Arsenal.
Pellegrini admitted he will need to treat Aguero in particular with extra care after the Argentina forward played through the World Cup with niggling injuries, including a muscle problem in his thigh.
"I think Sergio needs a very good pre-season," Pellegrini said.
"That's why for him it is very important to work two or three weeks intensely and then start playing. We hope this year he will not have injuries."
In addition to Kompany, Pellegrini acknowledged that defenders Martin Demichelis, Pablo Zabaleta and Bacary Sagna would not feature against Arsenal.
Similarly midfielders Fernandinho and Frank Lampard are set to miss out, along with injured striker Alvaro Negredo.
And Pellegrini accepted that not all of them will be ready for City's Premier League opener at Newcastle on August 17.
"They are not in the same moment, all of them," said the 60-year-old.
"We will see during next week which can be ready for Newcastle but I don't think they all will be ready."
City's star midfielder Yaya Toure was linked with a move away from Eastlands at the end of last season.
The Ivory Coast international was said to be unhappy with, amongst other things, the club's failure to recognise his 31st birthday with a cake.
However, Pellegrini reiterated that Toure is fully committed to City and has no issues with the club.
"There were a lot of reports about a lot of things," Pellegrini added.
"But Yaya doesn't have any problems. He works normally here, he wants to stay here, he is very happy here.
"The things that everyone talked about during the summer, I never heard Yaya talking about them, other persons yes, but not Yaya."