Point me to any statement made by NFL players that said so. There were no press conference, no speech after kneeling, no nothing from those players. And that's part of the problem, and that's why NFL approval rating fallen face first on the ground:
http://thehill.com/blogs/in-the-know/354365-poll-nfl-drops-as-favorite-us-sport
Would be surprised they'd have to, given the context of the situation. Then again if people are moving to watch baseball, doubtful how intelligent they are in the first place...