Marshall, who knelt during "The Star-Spangled Banner" in Thursday night's season opener against the Carolina Panthers, said following Broncos practice Monday that he recently lost his second endorsement deal since he took a knee.
The Air Academy Federal Credit Union parted ways with him shortly after Thursday's game, and on Monday, Marshall said CenturyLink, a cable/communications company, has ended its agreement with him.
Marshall said he had been signed on to promote the company's television and internet service.
"I just lost another endorsement,'' Marshall said. "But it's not going to make me lose any sleep. ... I understand there will be things that come up, criticism and support. I just have to do what I think is right.''
CenturyLink released a statement saying the company "completely [respects] Brandon Marshall's personal decision and right to take an action to support something in which he strongly believes.
"America is anchored in the right of individuals to express their beliefs. While we acknowledge Brandon's right, we also believe that whatever issues we face, we also occasionally must stand together to show our allegiance to our common bond as a nation. In our view, the national anthem is one of those moments. For this reason, while we wish Brandon the best this season, we are politely terminating our agreement with him."
Marshall also said he will meet with Denver police chief Robert C. White on Tuesday and with members of Denver's police union, the Denver Police Protective Association.
Marshall said he has heard from plenty of folks on both sides of what is now a national debate, and he's "trying to start a conversation ... based on social awareness.''
He said he continues to receives messages of support and criticism for his actions and that he "absolutely'' understands the passion of those who have either criticized him or supported him in recent days.
Marshall said he continues to monitor social media to see how people are reacting.
"Absolutely, a lot of it is military based because I read a lot of the comments that say, 'stay up for the people that fought for your right to stand,' but then the people that I talk to that are in the military say, 'I fought for your right to stand or sit, I fought for all your rights, so I support you,''' Marshall said. "Everybody doesn't believe that, but some people who actually serve this country do believe that."
On the prospect of some teammates opting to kneel during the anthem in future games, Marshall said: "It's cool if they do, I respect them for that, and it's cool if they don't. I respect that.''
"I talked to Colin Kaepernick and he said that he appreciated what I did,'' Marshall said. "... He said he was trying to get some things in place that would change some laws ... donating to organizations doing work at the ground level. One of my endgames [is] I will try to create a program that goes with that as well.''