Miami Dolphins players who protest on the field during the national anthem could be suspended for up to four games under a team policy issued this week.

[New: NFL suspends ban on national anthem protests amid talks with players' union]

The "Proper Anthem Conduct" section is just one sentence in a nine-page discipline document provided to The Associated Press by a person familiar with the policy who insisted on anonymity because the document is not public. It classifies anthem protests under a large list of "conduct detrimental to the club," all of which could lead to a paid or unpaid suspension, a fine or both.

Miami's anthem policy comes after the NFL decided in May that teams would be fined if players didn't stand during "The Star-Spangled Banner" while on the field. The league left it up to teams on how to punish players. None of the team policies have been made public.

[Opinion: NFLPA is going to lose its national anthem lawsuit and hurt the NFL in the process]

The NFL rule forbids players from sitting or taking a knee if they are on the field or sidelines during the national anthem, but allows them to stay in the locker room if they wish. The new league rules were challenged this month in a grievance by the players union.

The NFL declined to comment. Team officials had no immediate comment.

"Players who are on the field during the Anthem performance must stand and show respect for the flag and the Anthem," says the 16th and final bullet point in the list of conduct considered detrimental, below riding motorcycles during the season and disparaging teammates, coaches or officials including NFL Commissioner Roger Goodell.

The NFLPA said earlier this month that the NFL policy, which the league imposed without consultation with the players union, is inconsistent with the collective bargaining agreement and infringes on player rights. The filing will be heard by an independent arbitrator, an NFLPA spokesman said.

When the league announced the policy, Goodell called it a compromise aimed at putting the focus back on football after a tumultuous year in which television ratings dipped nearly 10 percent.

The union said when it filed the grievance that it proposed having its executive committee talk to the NFL instead of litigating. The union said the NFL agreed to those discussions.

In 2016, then-49ers quarterback Colin Kaepernick began protesting police brutality, social injustice and racial inequality by kneeling during the national anthem and the demonstration spread to other players and teams. It became one of the most controversial and sensitive issues in sports. Critics led by President Donald Trump called the players unpatriotic and even said NFL owners should fire any player who refused to stand during the anthem. Some players countered that their actions were being misconstrued and that they are seeking social change rather than protesting the anthem itself.

Trump's criticism led more than 200 players to protest during one weekend, and some kept it up throughout the season.

The NFL started requiring players to be on the field for the anthem in 2009.

"We want people to be respectful of the national anthem. We want people to stand," Goodell said at the May meetings, when he dismissed concerns about the lack of union involvement by contending the league met with countless players over the past year.

"We've been very sensitive on making sure that we give players choices," the commissioner added, "but we do believe that moment is an important moment and one that we are going to focus on."

The league and a coalition of players have been working in tandem to support player initiatives for a variety of social issues. The NFL is committing $90 million over the next seven years to social justice causes in a three-segment plan that involves league players.

Kaepernick didn't play at all last season and still hasn't been picked up by another team. He threw 16 touchdown passes and four interceptions in his final season in 2016. Safety Eric Reid, one of Kaepernick's former teammates and another protest leader, is also out of work.

Both have filed collusion grievances against the NFL.