Haener's performance was so bad, I think that the team will never be able to sell to the fanbase that he should start another game while Rattler remains healthy and available. It's unfortunate since Haener seems capable of performing in practice but isn't translating it to the field.
Rattler has a lot he can develop on, but I think he's never going to be in a position to show his full potential until the team eventually commits that he's the guy that's getting the start through a whole training camp. He needs every first team rep, to build rapport with the receivers, learn all the calls with the o-line, develop the nuances on selling play action, etc.