Chargers offensive tackle Russell Okung stood behind his teammates in the bench area, his fist raised, during the playing of the national anthem on Saturday night, via a photo from Jack Wang of the Los Angeles Daily News.
Okung did the same last season to protest social injustice and police brutality.
A handful of other players protested before games this week, prompting a response from President Donald Trump on Twitter.
Raiders running back Marshawn Lynch sat on the bench during the national anthem Friday night.
Three Seahawks left the field for the anthem before their game, and four Jaguars stayed inside for the anthem before their game.