First Matthew Stafford went down, then Jeff Driskel.
Blough went undrafted this year, then signed with the Browns. He went 25-43 for 271 yards, two touchdowns and two interceptions in four preseason games, before he was traded to the Lions for a seventh-round pick.
He's been taking first-team reps in practice throughout this week.
"(The quarterback) room in general, all three of those guys work really hard every single week, and I think obviously they follow along with Matthew and kind of his preparation and what he does," Matt Patricia said Wednesday. "They’ve a very competitive group, so they like to out-compete each other even with the preparation part of it. I think Blough falls right in line with those other two guys as far as the prep part of it.”
Blough will take on a Bears defense that's holding quarterbacks to an 86.3 passer rating and ranks fourth overall in the NFL.