Colin Kaepernick has been announced as the new face of Nike, and co-stars with Serena Williams in a campaign celebrating the 30th anniversary of its Just Do It slogan.

The American footballer and activist, who launched the movement of 'taking a knee' during the US National Anthem to protest racial injustice in 2016, took to social media to tease the upcoming campaign, posting 'Believe in something, even if it means sacrificing everything. #JustDoIt'.