Colin Kaepernick‘s national anthem protest seems to be slowly be gaining steam across the NFL.

During the NFL opener on Thursday, Broncos linebacker Brandon Marshall joined the cause by kneeling during the national anthem.

The Broncos linebacker was the only player from either team who kneeled before the game.

“While we encourage members of our organization to stand during the National Anthem, we understand and respect it being a personal decision,” the Broncos said in a statement.

Marshall is the third player in two weeks to join Kaepernick’s cause. Seahawks defensive back Jeremy Lane and 49ers safety Eric Reid both kneeled during national anthem before they played in their final preseason game.

When the rest of the NFL schedule kicks off this weekend, Marshall, Kaepernick, Lane and Reid could have some company in the protesting department. The Seahawks have hinted they plan on protesting as a team during their season opener against the Dolphins on Sunday.

Kaepernick has made it clear that he’s not going to stand for the national anthem until police brutality against minorities comes to an end.

“There’s a lot of things that need to change,” Kaepernick said on Aug. 28. “One specifically? Police brutality. There’s people being murdered unjustly and not being held accountable. People are being given paid leave for killing people. That’s not right. That’s not right by anyone’s standards.”

Source: CBS Sports / Broncos’ Brandon Marshall kneels during national anthem in NFL opener