San Francisco 49ers quarterback Colin Kaepernick has refused to stand for the national anthem in protest at what he sees as racial injustice.
He remained seated as the anthem was played.
“I am not going to stand up to show pride in a flag for a country that oppresses black people and people of color,” Colin Kaepernick explained.
Some fans booed Colin Kaepernick when he took to the field.
The San Francisco 49ers players said they supported Colin Kaepernick’s right to protest, which took place as the team hosted the Green Bay Packers in a pre-season game on August 26.
“We recognize the right of an individual to choose and participate, or not, in our celebration of the national anthem,” the 49ers said.
An NFL spokesman said players were “encouraged but not required” to stand during the anthem.
Colin Kaepernick has been outspoken on social media about race relations and a supporter of the Black Lives Matter movement.
He told NFL Media: “To me, this is bigger than football and it would be selfish on my part to look the other way.
“There are bodies in the street and people getting paid leave and getting away with murder.”
The NFL player appeared to be referring to police use of deadly force which sparked the Black Lives Matter protests.
In 2013, Colin Kaepernick led his team to the NFL’s title game, the Super Bowl, but has since lost his starting place.