"I'm going to take a fine this year, why not?" Casey told CNN at an NFL promotional event in London. "I'm going to protest during the flag. That's what I'm going to say now.
"... It is what it is, I ain't going to let them stop me from doing what I want to do. If they want to have these battles between players and organizations, this is the way it's going to be."
The NFL approved a new national anthem policy in May requiring players and league personnel on the sideline to stand. Players and personnel also have the option to remain in the locker room if they choose not to stand during the anthem.
Under the change, individual clubs have the power to set their own policies to ensure the anthem is being respected during any on-field action. If a player chooses to protest on the sideline the NFL will fine the team. Players could also be fined by their teams, per the policy.
Colin Kaepernick's decision to protest social inequality against minorities by taking a knee during the playing of the national anthem before a preseason game in 2016 spurred other players to protest. President Donald Trump has sharply criticized the actions of protesting players and called on team owners in September to "fire" them. The following week, players and team owners across the league took part in displays of solidarity during the national anthem. Some players continued their on-field protests for the rest of the season.
Casey told CNN his protests in 2018 will be a "continuation" of what he did last season when he raised a fist during the playing of the anthem.
"Around the NFL, guys are definitely not happy about it," Casey said about the policy. "I feel it's not right, I don't think it was a good decision for the NFL to come up with that ruling. But they have their reasons for what they've done."
Casey said he was prepared to face "blowback" from people who disagree with his decision.
"It is what it is, at the end of the day, I don't pay no mind to it. I'm going to do what I do that's going to bring light to my community. ... I will continue to use my platform to keep on speaking up."