The boss, who has expressed sympathy for the youngster’s limited game time in recent weeks, reiterated his belief that the Academy graduate is ready to play week in week out for the first team.
“He is 19-years-old. He has played quite enough minutes in this period and he will play a lot in this season and the next seasons.
“Phil is in the first team for City because he is ready to play every single game.
“He has everything to play. Of course, he has many things to learn, but so do guys who are 30-years-old.
“He’s young. The skills are there but he can improve and that’s why I want to help him.”
All four have made their debuts under Guardiola, while Garcia and Harwood-Bellis, with a combined age of 35, were deployed at the heart of City’s defence against Preston North End in the Carabao Cup.
They made a promising start, but the Catalan acknowledges the challenge of blooding youngsters in a team fighting for silverware on four fronts.
“This team needs to win titles,” he added.
“The process for young players needs time and the best way is step by step, but the demand of this Club is to be there all the time in all competitions.
“For that, we need the players that we have.
“The young players can help the other ones, but if the basis [of the team] is the young players, it’s not possible.”