Guardiola was speaking after victory over Bournemouth on Tuesday night.
Despite City's strength in depth, Guardiola wants to work with a leaner squad next term.
He said: "I said to the club I don't want that (a bigger squad).
"I don't want to leave five or six players in the freezer. I don't want that. I will quit. Make a shorter squad, I will stay."
"I don't want that"
City's manager admits he is finding increasingly difficult to leave accomplished players out of his matchday squads.
Guardiola also stated: "Maybe (for) three, four months we couldn't select 11 players, we didn't have defenders, it was so difficult. After people come back but next season it cannot be like that.
"As a manager I cannot train 24 players and every time I select I have to have four, five, six stay in Manchester at home because they cannot play. This is not going to happen. I said to the club. I don't want that."