I would almost never advocate in favor of replacing your season-long starting QB with the backup QB because the starter was injured and the backup came in a played well.Altmyer will start
The only scenario I could envision where you must do that is when the backup comes in cold on the final drive, converts a long 4th, and then thows the game-winning TD on a dime with 50 seconds left. And then the following week breaks the record for most passing yards for an Illinois QB at Memorial Stadium, and the second most in Illini history, and throws a walk-off TD in overtime.
Sometimes the circumstances are just too crazy not to compel you to break convention. There’s just no way to send Paddock back to the bench now.
And in a weird way you’re almost protecting Altmyer by doing that. If Altmyer goes back in as starter and struggles even the slightest, the calls to pull him will be deafening. And the worst case scenario would be that Altmyer throws a few picks or can’t get the offense going and gets pulled mid-game. It’s just not a good situation for a young QB who is still developing.