He is talking about quitting because he never starts

Before the parent takes over the conversation, I would want the player to have an honest one with the coach. At U15, repeatedly starting on the bench can become more than a minutes issue. The player can start reading it as “this is what I am in this team.” That is why the coach needs to explain what they see, what the player's current role is and what could realistically change. Help your son prepare two or three questions: What am I doing well? What is keeping me from starting more often? What can I influence over the next month? The conversation matters here. If the answer is vague every time, that is useful information too. A parent can support afterwards, but giving the player a voice first is an important part of helping them handle older youth football.