(RNN) - NFL Commissioner Roger Goodell said Wednesday that, beginning next season, players on the field who do not stand and "show respect" during the national anthem will be subject to discipline.
Team owners unanimously approved the rule change at the spring meeting held in Atlanta this week. Players will be given an option to remain in the locker room without penalty while the anthem is played before kickoff.
The NFL said teams would be fined if personnel on the field do not participate in the anthem ceremony, although it did not state the amount they would be penalized. The clubs were given the power to create their own rules dealing with their players, coaches and other staff.
The rules state the commissioner has the power to "impose appropriate discipline" on league personnel who do not follow the rule as well.
"The efforts by many of our players sparked awareness and action around issues of social justice that must be addressed," said Goodell in his statement Wednesday. "The platform that we have created together is certainly unique in professional sports and quite likely in American business. We are honored to work with our players to drive progress.
"It was unfortunate that on-field protests created a false perception among many that thousands of NFL players were unpatriotic. This is not and was never the case."
The NFL Players Association released a statement soon after the announcement, saying it would review the policy and challenge any part that's inconsistent with the collective bargaining agreement. The union stated it had not been consulted by the league.
"The vote by NFL club CEOs today contradicts the statements made to our player leadership by Commissioner Roger Goodell and the Chairman of the NFL's Management Council John Mara about the principles, values and patriotism of our league," said the NFLPA in its statement.
The old policy required players to be on the field for the playing of the anthem but only said they should stand, with no penalty for not doing so.
Multiple players took part in kneeling, locking arms or other showings of discontent in the past two seasons as "The Star-Spangled Banner" played and the American flag was recognized at NFL stadiums. Former San Francisco quarterback Colin Kaepernick began sitting, and later kneeling, during the 2016 preseason in protest of police violence against minorities in the U.S.
Much of the protesting had stopped until President Donald Trump injected himself into the conversation, saying players who kneel should be fired. Several more players began protesting or taking part in showings of unity in the weeks that followed, putting the league's representatives in the middle of conversations on patriotism and racism.
The league has blamed the controversy for being part of a decline in overall TV ratings.
Kaepernick and former teammate Eric Reid have ongoing lawsuits against the NFL, alleging the teams colluded to keep the players out of the league.