Dan Orvlosky and Marcus Spears both believe Khalil Mack and the Bears will come out strong against the Lions due to QB issues in Detroit. (0:32)

The Detroit Lions will start undrafted rookie David Blough at quarterback on Thanksgiving against the Chicago Bears due to injuries to Jeff Driskel and Matthew Stafford.

Driskell will serve as Blough's backup, and quarterback-turned-tight-end Logan Thomas could be a potential fallback option.

The Lions acquired Blough at the league's cut-down deadline after the preseason in a trade with Cleveland. They've kept him on the roster all season as a third quarterback, but he has yet to play a snap. Now he'll start.

Blough's opportunity came because Driskel, who has started in place of Stafford, has been dealing with a hamstring injury suffered Sunday against Washington. Driskel said Tuesday that the hamstring has "gotten better" day by day, but apparently not enough to start. In his two media sessions this week, Lions coach Matt Patricia said that if need be, Driskel could stay in the pocket more, though that would take away the mobility part of his game.

In preparation for this, the Lions have given Blough first-team reps during Detroit's two walkthroughs this week.

"We'll have competitive periods against offense versus defense, along with our preparation periods that we use each week," Patricia said. "We like to take those different kind of chances during the week to mix up some of the huddles and who is out there and who is not. We do it really at all positions, and certainly, Blough is one of those guys that it's important for us to do that with, too."

Blough will be the third starting quarterback for the Lions in a month after having Stafford start every game since the end of the 2010 season. He'll also be just the third quarterback since 1950 to make his first career start on Thanksgiving, joining Drew Henson (Cowboys, 2004) and Kent Graham (Giants, 1992), according to Elias.

Blough was Purdue's starting quarterback last season, throwing for 3,521 yards, 25 touchdowns and eight interceptions.