Cleveland Browns tight end Seth DeValve -- the first white NFL player to kneel during the national anthem -- says he demonstrated on Monday night to support his African American teammates. 

12 Browns players in total knelt in a circle before Cleveland took on the NY Giants -- the players included stars like Jabrill Peppers, Calvin Pryor, Isaiah Crowell, Kenny Britt and Duke Johnson

But DeValve made the biggest splash ... just days after Michael Bennett said a white player kneeling would make the protest more effective. 

DeValve -- who's married to a black woman -- heard Bennett loud and clear and heeded the call. 

After the game, the Browns protesters explained their demonstration -- saying they wanted to come together as men to combat all the hate and injustice in the world.