Okay Okay, you don't want the spotlight, but you still wanna be fairly involved. This would be a great role to audition for if you want to still be really in the series but you've got a busy life style and don't have as flexible of a recording schedule as some of the rest of us who don't touch grass lol. A supporting character is still an important role and your contribution the series will not go unnoticed! It just means your character may be less focused on and have a little less screen time than someone in the main group. 
(Again, like with the main characters role, these audition lines are a suggestion as your character would be part scripted and part improv with your own touch to it, so say what you think you'd say as a character in this apocalypse ridden world the way you think you might say it)