It looks like Purdue will go back to Austin Appleby on Saturday as David Blough, Purdue's starter for the past 8 games, is still battling a concussion from the Iowa game on Saturday:

Hazell: Blough still foggy right now. It will be a day-to-day thing. Probably doubtful for this week after concussion vs Iowa — mike carmin (@carminjc) November 24, 2015

Purdue is going to Appleby because, really, they have no one left. Elijah Sindelar is redshirting and both he and the staff has said the redshirt will be burned if an injury occurs to Appleby that knocks him out of the game and it is still winnable. If Appleby is knocked out for only a few plays Purdue will turn to freshman walk-on Aaron Banks, who is the only other QB on the roster. Bilal Marshall, a HS QB who has thrown a few passes in his career, is also an option.

Banks is an interesting option. he was recruited by Illinois, Indiana, and Cincinnati and played well at Brebeuf.