The NFL Players Association announced on Monday that it is sending a memo to all of its teams that players are not permitted to participate in the National Anthem, with the exception of a few teams that are allowing players to stand during the anthem.

The memo said players have a constitutional right to protest peacefully, but if they feel compelled to do so, they must do so responsibly.

The league has yet to release an official statement about the memo.

However, it is believed that players and owners will eventually take a stand during games and protests by players and the fans, according to sources familiar with the matter.

The players have had a busy offseason, with several players, including the New England Patriots wide receiver Julian Edelman, former Atlanta Falcons wide receiver Julio Jones and New York Jets wide receiver Brandon Marshall, all taking part in protests against police brutality, police brutality and racial profiling.