Siemian (shoulder) has been ruled out for the remainder of Thursday's game, Patrick Smyth of the Broncos' official site reports.
Siemian took a hard hit from Barkevious Mingo in the first quarter, falling awkwardly on his left shoulder in the process. Before being carted to the locker room, Siemian was five of nine for 67 yards and an interception. Brock Osweiler, who takes over under center, is the only active quarterback left for the Broncos.