'We believe Colin is one of the most inspirational athletes of this generation, who has leveraged the power of sport to help move the world forward,' Gino Fisanotti, Nike's vice president of brand for North America, told ESPN.
'We wanted to energize its meaning and introduce 'Just Do It' to a new generation of athletes,' added Fisanotti, who said the campaign is aimed at 15- to 17-year olds.
Kaepernick has remained unsigned since March of 2017 after a season in which he refused to stand for the national anthem as a way to raise awareness about inequality and police brutality against minorities.
Since starting the demonstrations during the 2016 NFL preseason, Kaepernick has been joined by scores of other NFL players in the face of intense criticism, namely from President Donald Trump, who has referred to the protesters as 'sons of b******.'
In early August, Trump demanded on Twitter that the '$40,000,000 commissioner' of the NFL suspend players for a whole season if they kneel during national anthem more than once.
'The NFL National Anthem Debate is alive and well again - can't believe it!,' Trump wrote in the tweet.
The demonstrations were primarily a reaction to the deaths of African-American men at the hands of law enforcement.
The NFL is still working towards a resolution on a national anthem policy. In May the owners announced a new set of rules allowing players to remain in the locker room during the anthem while requiring any team personnel on the field to stand. Teams with personnel in violation of the new policy would have been subject to fines, and those teams would have the right to fine their own players as they saw fit.
However, since then the league and the NFL Players Association have been meeting in East Rutherford, New Jersey to work towards a compromise on the issue. According to an ESPN report, both sides are 'encouraged' by the dialogue, but a resolution is not expected to be made by Thursday's opener.
While the uproar over the protests has continued, Kaepernick has pressed ahead with his lawsuit against NFL owners, claiming that they have colluded to keep him out of the league, in violation of the collective bargaining agreement.
Kaepernick recently scored a legal victory when an arbitrator denied the league's request to throw his suit out last week.
The case hinges on whether or not the owners worked together to keep him out of the league, and while that may be difficult to prove, he's not the only former 49ers player in this situation.
Pro Bowl safety Eric Reid, who was the first of Kaepernick's teammates to protest alongside him, also remains unsigned with the NFL season set to start Thursday night.
And like Kaepernick, Reid has hired attorney Mark Geragos to represent him in his collusion lawsuit against the league.
The two players were recently seen watching another Nike athlete, Serena Williams, at the US Open in New York.
Williams, who is also involved with the 'Just Do It' campaign, voiced her support for Kaepernick and Reid after beating her sister Venus last week.
'I think every athlete, every human, and definitely every African-American should be completely grateful and honored how Colin and Eric are doing so much more for the greater good, so to say,' Williams said. 'They really use their platform in ways that is really unfathomable.
Other athletes involved in the latest installment of the 'Just Do It' campaign are New York Giants wide receiver Odell Beckham Jr., and Seahawks rookie linebacker Shaquem Griffin, who made it to the NFL despite being born without a left hand.
Several influential NFL players have argued that Kaepernick deserves to be in the NFL after leading the 49ers to three NFC Championship Games and one Super Bowl during his six-year career.
Both New England Patriots quarterback Tom Brady and Green Bay Packers quarterback Aaron Rodgers have said they believe he should be on a roster, with Rodgers going so far as to tell ESPN he thinks the Wisconsin native is being blackballed.
'I think he should be on a roster right now,' Rodgers said. 'I think because of his protests, he's not.'
In 69 games (58 starts), all with the San Francisco 49ers, Kaepernick was 28-30 and had thrown for 12,271 yards, completing 59 percent of his passes and tossing 72 touchdowns and 30 interceptions.
Kaepernick, who hasn't played since January 1, 2017, also has 2,300 career rushing yards and 13 touchdowns on the ground.
He hasn't had a workout with any NFL teams since becoming a free agent.
Kaepernick met with Seattle during free-agency in the summer of 2017, but the team opted instead to sign Austin Davis to back up Russell Wilson. Prior to this season, the Seahawks signed journeyman backup Stephen Morris instead of Kaepernick, only to cut Morris and sign Brett Hundley, who has a career quarterback rating of 67.9 - significantly lower than Kaepernick's career mark of 88.9.
Protests during the national anthem were not unheard of before 2016.
Former NBA player Mahmoud Abdul-Rauf refused to stand for the anthem in 1996 because, he explained, he saw the flag as a symbol of tyranny. After receiving several fines, Abdul-Rauf and the league eventually worked out a compromise where he would stand in prayer during the anthem.
Two years later he left the NBA to play for Istanbul's Fenerbahçe.
Even Jackie Robinson expressed misgivings about the national anthem in his autobiography, 'I Never Had It Made,' with Alfred Duckett in 1972.
'I cannot stand and sing the anthem,' wrote Robinson, who broke Major League Baseball's color barrier when he debuted for the Brooklyn Dodgers in 1947. 'I cannot salute the flag; I know that I am a black man in a white world. In 1972, in 1947, at my birth in 1919, I know that I never had it made.'
