With unheralded quarterbacks like Trevor Siemian, Jacoby Brissett and Gardner Minshew thrust into starting roles already in 2019, calls for Kaepernick to at least be signed as a backup flare up with every injury or bad performance. Some players still use the platform of the country’s most popular sport to protest, as Kenny Stills demonstrated last month. The league, meanwhile, started the season with a saccharine promotional campaign to turn protest to progress, as a favorite talking point of N.F.L. executives goes.

Still, the league has moved mostly beyond Kaepernick, leaving his relationship with Nike as the most public platform for the famously quiet activist.

Initially, the limbo of his playing career appeared to benefit both the apparel giant and Kaepernick. For Nike, the relationship resulted in tens of millions of dollars of free advertising and heightened credibility with the young, diverse consumers who look up to the player. For Kaepernick, the contract was lucrative and the might of one of the world’s most powerful companies helped his goal of raising awareness of police brutality and systemic racial inequality.

Signing Kaepernick and featuring him in the commercial immediately struck gold for Nike.

Of course, there were cries for boycotts of the company’s apparel and videos of people burning their Nike shoes in protest, the sort of impassioned response Nike courts and capitalizes on to remain in the news far longer than a 60-second commercial. Nike’s stock surged in the days after the campaign debuted, increasing the company’s value by more than $6 billion two weeks later.