The NBA issued a memo to their 30 teams reinforcing its rule that players and coaches must stand for national anthem.

The memo was distributed by deputy commissioner Mark Tatum. It instructs teams that "the league office will determine how to deal with any possible instance in which a player, coach, or trainer does not stand for the anthem."

The memo states that individual teams "do not have the discretion to waive" the rule that players, coaches and staff stand for the anthem.

The league has the discretion to discipline players who violate the rule. It is not clear if the league would exercise it in the event of any protest.

The league also does not want teams independently disciplining players, sources say, and has encouraged open dialogue within teams.

The memo also suggests teams might prepare a video tribute or public service announcement featuring "team leadership speaking about the issues they care about."