Siemian completed 11 of 21 pass attempts for 149 yards and two touchdowns in Sunday's 21-14 loss to the Raiders.
Starter Paxton Lynch left the game with 4:58 left in the third quarter and the Broncos down 21-0. The 25-year-old led a three-and-out followed by consecutive touchdown drives before the Raiders were able to run out the clock and seal the win. If Lynch can't play in Week 13, Siemian will likely draw the start in Miami.