You want to play the new champion?
Ok, no problem with that. Expecially in Normals since you got to elarn it somewhere.
Just don't use him/her no matter what position you are.
While you might go bad yourself you might really gimp your team value. Like Top Taliyah, it makes no sense not because you can't win the matchups but because then your team lacks a potential front laner or a split pusher.