Asked about Grealish's inclusion in Carsley's recently released squad in a press conference, Guardiola responded: "It's a question for the England manager - I'm not involved. They can select who they want.
"Jack trained today (Friday) and believes he can help us - I'm not the guy to say you cannot go (on international duty). But for my team, he's not fit. He cannot play. All I can say is that for a couple of days over two weeks he didn't train but the people from England believe he can help them. So go.
"They can select who they want. All I’d say is the day after Wolves, he was injured, 17 days out and today [Friday] was the first training with the team."
Guardiola sarcastically added: "The manager from the UK knows batter than me."
The Catalan also claimed that the City medical department "hasn't told me they have spoke" with their England counterparts, although the English FA has released a statement confirming they did consult Manchester City doctors.