Colin Kaepernick tweeted the ad with the words, "Believe in something, even if it means sacrificing everything. #JustDoIt."
Colin Kaepernick will be the face of Nike's 30th anniversary "Just Do It” campaign, reports ESPN's Darren Rovell.
According to Rovell, Nike has been paying Kaepernick all along and "waiting for the right moment," which is now. Nike signed Kaepernick in 2011, but has not used him over the past two years.
"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.
Kaepernick tweeted the ad which has the words, "Believe in something, even if it means sacrificing everything. #JustDoIt."
Nike is the NFL's official uniform sponsor.
Other athletes in the new campaign include Serena Williams, Odell Beckham Jr., Shaquem Griffin and LeBron James.
The former 49ers quarterback began kneeling during the 'Star-Spangled Banner' in August 2016 as a means of protesting racial inequality and police brutality. Dozens of other NFL players, as well as numerous other athletes across America, ultimately joined him. The protests grew during the 2017 season after President Donald Trump criticized NFL players who chose to follow suit. Trump said owners should "fire" NFL players who protest the anthem and referred to them as "son[s] of b------". Players responded by protesting en masse.
Kaepernick hasn't played since the 2016 season. He filed a grievance against the NFL for collusion in October 2017 after another team did not pick him up after opting out of his 49ers contract in March of the same year.
He won the summary judgment phase of his collusion case last week.