Going with Rattler would be a little odd, considering Haener is the backup and Rattler’s been inactive on game days. But it might just happen that the team likes Haener better in the emergency role and would prefer to game plan for Rattler. Same thing happened to Jameis Winston and Taysom Hill a few years ago after Drew Brees got hurt. So this wouldn't be without precedent.
Everyone says Rattler’s been performing well in practices and has leveled up since training camp. They rave about his big arm and play-making ability, which are things we all saw throughout camp. But no one could really say how his reps on the scout team would translate into running the Saints offense. So if it happens to be Rattler, everyone is going to find out how it looks on the field against real competition at the same time as us.