Broncos' Brandon Marshall kneels during national anthem

DENVER - 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.

Marshall sounded a similar theme after Denver's 21-20 win.

"I'm not against the military, I'm not against America," he said. "I'm against social injustice."

Kaepernick's gesture 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.

Broncos Super Bowl MVP Von Miller said he supported Kaepernick, too. "I'm not going to kneel for the national anthem but I feel it should be a change. His actions really brought the topic, brought it into the conversation. I'm with Colin all the way."