Man, I play ball too and that would be horrible. What school level are you in? Highschool, middle school? If middle school, it doesn't mean sh**, forget about it. If highschool, then let me know are you a freshman, sophomore, junior senior? If you're a freshman and you played basketball in middle school you need to meet your coach and talk to him about your injury. He could find something to do about that, like talk with your middle school coaches and see if you could fit into high school bball. When I was a middle schooler in 8th grade bball, our coaches got us to talk to the highschool coaches, and all the kids going to that highschool got into a 5v5 tournament while the coaches watched us to see how we knew the game and played. If you had anything like that, then just tell him about how you played and any other proof needed.
If you're a sophomore, junior or senior, you have to have played on the year before or they honestly won't care too much. Like for example, a senior who got injured but played all 3 years of highschool you're certain to make the team even though you can't try out. And a sophomore that killed it on the freshmen team, you're bound to make it.
If you didn't play basketball at all the year before, then I can't decide. I would talk to the coach like this when he's not busy
"Hey Coach, I'm really interested in joining the basketball team and have spent 4 months preparing and working on my craft, but I broke my arm from a scooter accident. Is there anything you can do to help me out?"