The NFL will try to find a compromise over the issue of players protesting during the national anthem when team owners meet this week.
Colin Kaepernick first sat down during the US national anthem in August 2016, before opting to kneel instead, in protests against racial injustice.
Other players followed suit, and the protests spread after criticism from President Donald Trump last month.
An NFL spokesman said he anticipated "a very productive presentation".
The meeting will take place in New York on Tuesday and Wednesday.
Last week, NFL commissioner Roger Goodell wrote a letter to teams in which he said disputes over the protests threatened "to erode the game's unifying power".
He added: "Like many of our fans, we believe that everyone should stand for the national anthem. It is an important moment in our game.
"We want to honour our flag and our country, and our fans expect that of us.
"We also care deeply about our players and respect their opinions and concerns about critical social issues."
Kaepernick, 29, has been without a team since he opted out of his contract with the San Francisco 49ers in March.
On Sunday it was announced he has filed a grievance against team ownershe believes are conspiring not to hire him because of his protests.