Random House did not immediately respond to a request for comment from The Times.
One World, originally founded in 1991 and relaunched this year, is headed by publisher and editor-in-chief Chris Jackson. The imprint has previously published Joe Tone's "Bones: Brothers, Horses, Cartels, and the Borderland Dream" and Ta-Nehisi Coates' bestselling "We Were Eight Years in Power: An American Tragedy."
Kaepernick started a protest movement in 2016, when he started refusing to stand while the national anthem was played before 49ers games.
"I am not going to stand up to show pride in a flag for a country that oppresses black people and people of color," Kaepernick explained to NFL Media. "To me, this is bigger than football and it would be selfish on my part to look the other way. There are bodies in the street and people getting paid leave and getting away with murder."
The protest launched a bigger movement, with several NFL players sitting or kneeling during the national anthem this season. The protesting players have been met with fiery denunciations from President Trump, who has accused them of disrespecting the anthem.