Kubiak added Siemian has a sore shoulder but likely will return to practice Tuesday.
While Mark Sanchez might be able to recover at some point during the season, Kubiak's announcement puts more faith in the second-year quarterback out of Northwestern. The seventh-round pick already had a year in Kubiak's system and was pegged as a surprise candidate all along to upend the more experienced Sanchez and first-round pick, Paxton Lynch.
Why is the third preseason game crucial? Typically teams use the third game as their most realistic dress rehearsal during the four-game warmup series. Siemian should easily get his most playing time of the preseason and will get to game plan for his opponent -- something teams rarely do during the first or second preseason game. The planning can have a massive impact on a quarterback's performance and negate some of the assignment errors that often populate the preseason.
The ball seemed to be in Sanchez's court after Siemian ended his playing time against the 49ers with a pick-six. Sanchez, however, lost two fumbles before the half and couldn't find a rhythm to start the third quarter. Once the Broncos did not secure a deal with Colin Kaepernick this offseason -- or venture too deeply into the waters for Sam Bradford -- Sanchez was widely believed to be the starter by default.
A sound performance by Siemian could close the book on that question for now.
» As we wrote Sunday, DeMarcus Ware (back) is set to hit the practice field. The team officially removed him from the non-football injury list Monday and he will be on the practice field Tuesday.