Broncos linebacker Brandon Marshall, a college teammate of Colin Kaepernick, took to a knee during the playing of the National Anthem before Denver's season opener against Carolina.

Kaepernick refused to stand for the anthem during San Francisco's preseason games , explaining it was to protest racial oppression and police brutality in the United States.

It opened a wide debate and put the microscope on a pregame tradition that has, for decades, been routine.

Marshall was standing with his hand over his heart during the Anthem before a preseason game on Aug. 20.

He made no mention of his plans for Thursday's opener but shortly after the large American flag was unfurled, the fifth-year linebacker out of Nevada went to the end of a long row of Broncos and took a knee.