Colin Kaepernick has yet to throw a regular-season pass, but the 49ers' backup quarterback's decision to kneel during the national anthem to protest social inequality has made an impact that extends well beyond a football game.

As Kaepernick continues to protest, he has been joined by other NFL players, and athletes -- both professional and amateur -- in other sports. It has become a divisive topic nationally, especially in light of recent shootings of African-American men by police officers in Tulsa, Oklahoma, and Charlotte, North Carolina. On Friday night, Kaepernick was in Oakland at Castlemont High School, where he took a knee during the anthem while the Castlemont players laid on their backs with arms up.

The image is courtesy of ESPN analyst and former Raiders player Kirk Morrison's Twitter feed.

As notes, the visual is reminiscent of 46-year-old Charles Kinsey, who was shot in North Miami over the summer while lying on the ground with his hands raised.

Kaepernick also spoke to Castlemont players before the game.

"You are important. You make a difference. This matters. Everything you do matters," Kaepernick said. "Look out for one another, lift each other up. That's what this is all about. I had to come support y'all, because the same way y'all took a stand and stood with me, I had to come out here and stand with y'all. So I appreciate what y'all did. I love y'all. Y'all my brothers. I'm here with you."

Castlemont protested before their previous game.

Meanwhile, Oakland Unified School District's Honor Band also waged a silent protest earlier in the week, taking a knee while performing before the Oakland A's game on Tuesday night.

"Near the end of the song, most of the 155 middle and high school students took a knee in protest against police brutality and unfair treatment of people of color in America," read the OUSDNews Instagram posting. "The crowd responded with enthusiastic applause."

On Thursday, 49ers coach Chip Kelly was asked about Kaepernick's story making national headlines.

"I think it's an issue," Kelly said of the recent shootings. "You look at what's gone on in Tulsa and in Charlotte the last two nights, it's an issue that's at the forefront of our country. And it needs to be addressed and be taken care of because what's going on is not right.

"So I think, again, [Kaepernick's] shedding light on a situation that is heinous. And shouldn't happen in this country. We all have inalienable rights as a citizen and this country and they're being violated. And I think that's what Colin is standing up for."