I agree that there is no need to force himself into sports, and that ultimately, one would like to see him comfortable and confident in himself, without reference to other people's standards...but I do get that it can feel very isolating, especially for boys, if sports is not your thing. If he has an interest in sports, but just can't get his body into it, or lacks the competitive instinct that appears to be essential to sporting success, perhaps he can turn his math brain to pro sports statistics. That's one avenue to sports-mad-boy street cred.