Former San Francisco 49ers quarterback Colin Kaepernick is part of a new Nike campaign to mark the 30th anniversary of the sporting equipment giant's iconic "Just Do It" slogan, reports said Monday.
Kaepernick, who triggered a political firestorm after kneeling during the US national anthem in 2016 to protest racial injustice, has not played in the NFL since early 2017.
The 30-year-old is suing the NFL, claiming he has been frozen out of the league by team owners because of his activism.
The new Nike adverts, which were unveiled just days before the kick-off of the 2018 NFL season, show a portrait of Kaepernick with the slogan: "Believe in something. Even if it means sacrificing everything."
Kaepernick posted the advert on his Twitter account followed by #JustDoIt.
ESPN reported that Nike had kept Kaepernick, who signed a sponsorship deal with the company in 2011, on its payroll throughout the controversy of recent 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, was quoted by ESPN as saying.
The advert comes just days after Kaepernick was cheered by spectators when he appeared alongside fellow player and activist Eric Reid at the US Open tennis tournament to watch Serena Williams on Friday.
Kaepernick's protests have become a bitterly divisive issue amongst NFL fans after President Donald Trump reignited the controversy.
Trump described players like Kaepernick who knelt for the anthem as "sons of bitches" who should be fired.
Trump has repeated those criticisms frequently over the past year, even suggesting at one stage that protesting players "shouldn't be in the country".
In June, Trump cancelled the visit of the Super Bowl champion Philadelphia Eagles to the White House after several players indicated they would not attend.