Colin Kaepernick headlines Nike's 30th anniversary of 'Just Do It' campaign

Colin Kaepernick is back -- at least as far as Madison Avenue is concerned.

The former NFL quarterback, who is suing NFL owners for colluding to keep him out of the league, is one of the faces of a new Nike campaign meant to commemorate the 30th anniversary of the brand's iconic "Just Do It" motto.

The new ad, which Kaepernick shared on social media Monday afternoon, features the message: "Believe in something. Even if it means sacrificing everything."

Nike signed Kaepernick in 2011 and kept him on its endorsement roster over the years. The company has not used him in the past two years, but have used him since 2011. 

"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.

Other athletes in the Just Do It campaign include Odell Beckham Jr., Shaquem Griffin, Lacey Baker, Serena Williams and LeBron James.

"We wanted to energize its meaning and introduce 'Just Do It' to a new generation of athletes," Fisanotti said.

Fisanotti said the new version of the campaign is meant to specifically speak to 15- to 17-year olds.

Kaepernick was the one of the first players to take a knee during the playing of the national anthem in 2016 to protest racial injustice. No team signed him as a free agent in 2017.