Mike Klis of KUSA reports that tests show that Siemian suffered a subluxation in his left shoulder. Per the report, Siemian will miss the rest of the season as a result and may need to have surgery to repair the injury.
Siemian started the first seven games of the season for the Broncos before being benched in favor of Brock Osweiler. Osweiler later gave way to Paxton Lynch and Siemian returned to the lineup after Lynch hurt his ankle in a Week 12 loss to the Raiders.
Osweiler took over and played well on Thursday night. Lynch is expected to practice next week for the first time since getting hurt.
Siemian has been the primary starter in Denver the last two years, but his future in Denver along with that of the other two quarterbacks is uncertain as the team is expected to look for a surer answer at quarterback this offseason.
UPDATE 2:16 p.m. ET: Broncos coach Vance Joseph confirmed Siemian is done for the season. He said no surgery is planned right now.