Hart, 29, has lost his place as City's first-choice stopper since the arrival of Pep Guardiola and has been on the bench for their first three games of the season, with Willy Caballero preferred in goal.
women magista obra Guardiola has told Hart he is free to leave the Etihad Stadium if he desires but Allardyce said on Monday that the former Shrewsbury youngster will definitely be in the first squad he names since being appointed England boss a month ago.
That squad will be announced on Sunday, a week before Allardyce's Three Lions take on Slovakia in their World Cup qualification opener in Trnava.
While Allardyce is ready to retain the services of Hart for now, the 61-year-old has warned that he must be getting regular football to continue to be selected.
"Eventually, in the end it is critical," Allardyce said when asked how important it was that Hart was in the Man City side.
"If it's a short period of time, maybe not. Then they come back in the team and everything goes fine.
"If it goes for a longer period of time then I think it's difficult then to select them, based on how they feel, never mind from a training point of view. Can they go and play at that level having not played for their own team for a considerable amount of time? So it is a concern.
"At the moment, it's a difficult decision in the goalkeeping area, there's no doubt about that. It's one I could have done without but you have to deal with it."
Allardyce said he will seek to talk to Guardiola around his decision to drop Hart, for which he cited the goalkeeper's perceived poor footwork as a reason for opting with Caballero.
"Well I'll go and speak to them about that, Pep and Joe, sooner or later," he said.
"If I can get the chance to go and see Pep I'd like to listen to him anyway, never mind just about that. I like the two full-backs coming inside, that'll be the next generation of 'who's going to copy that?'."
Like his predecessor Roy Hodgson, and as proved by his revelation that Hart will be in his first squad, Allardyce has come to the realisation that some of the players he picks may not be automatic choices with their clubs.
women superfly mercurial v But he did single out Manchester United forward Marcus Rashford, who burst onto the scene last year and was a surprise inclusion in Hodgson's squad for Euro 2016, as an example of someone who may have to take a step backwards before earning a spot in his England set-up.
superfly mercurial pink women Asked if he knew what his starting XI would be in Slovakia, Allardyce said: "No, I know the basis of it but I don't know the team. I don't know it all just yet. There's other people to consider as well as the European squad that went to the Championships.
"There's other people who have started this season who were not in the Euros squad that we've got to consider as well. I'm not going to say specifically say who they are at this moment. They will all come into play for the possible squad selection for the first get together.
"Rashford is not playing now. It makes it harder for me now to select him, as exciting as he was last year and how he burst on the scene.
"At such a young age, do I say 'go play in the Under-21s. Get used to international football there, play regularly there and it will help you eventually, hopefully break into Manchester United's team and then break into the England senior team.' You've got all those scenarios to consider."
superfly mercurial women Allardyce has also yet to reveal whether Wayne Rooney will retain the captain's armband in his new set-up, after admitting at his unveiling last month that he was still unsure who his skipper would be.
women ace 16+ purecontrol He is still not ready to announce who England's new captain will be, saying: "We will announce the squad then we'll meet up and the first thing I would probably choose to tell the public and the media would be who is going to be the captain so we can get that one out of the way. The team selection and the first XI will be later on in the week.
"He's (Rooney) the most successful England player for the last decade, he's broken every record at league level, Champions League level and international level, so yes, we should talk very much about Wayne and about how good he is, what a fantastic player he is and what a really, really good captain he is."
