Kaepernick, an unsigned free agent, began kneeling during the national anthem in 2016 to bring attention to police brutality against unarmed African Americans, as well as other racial injustices.
Other players joined him in kneeling during the anthem, drawing the ire of President Trump and sparking a debate over the players’ demonstrations.
In 2017, the quarterback opted out of his contract with the 49ers when it appeared the team would cut him during the offseason. He is now suing the NFL, alleging team owners are colluding to prevent him from signing with another team. An arbitrator ruled last week that his grievance will go to trial.
NFL owners approved a new policy in May requiring players to either stand during the anthem or remain off the field. That policy has yet to go into effect as negotiations between the league and the players’ union over the policy continue. Several players raised their fists, kneeled or stayed off the field at preseason games over the past several weeks.
Nike did not immediately respond to requests for comment.