For any former high school athletes.Am concerned about my brother?

Ok, about a year ago I noticed my younger brother started acting differently. He dropped out of baseball which is the sport he's been playing since he was 5. My parents freaked out because he loves baseball. My dad even made him go back to the coach and ask to get back on the team. But then he stopped going to practices and the coach threatened to kick him off if he didn't get it together. His response was to resign. Now he's flunking out of school. None of his friends talk to him anymore. He's gained about twenty pounds and although he's barely graduating now he's saying he doesn't want to go to college. We tried to make him see that the school is accepting him even though his grades dropped but he doesn't care. My bf believes he's depressed. He told me there's a lot of pressure on hs athletes and it may have driven my brother to depression. I just want him to go back to normal, and I know my family can help him. My father won't even hear about him going to a therapist. Any advice?