Several players followed suit, and the 2017 season was marked by numerous protests during the pre-game anthems - much to the disgust of USA president Donald Trump.
Nike did not immediately return Business Insider's request for comment on the boycott threats. Others vowed to wear their Nike apparel more frequently or to go out and buy Nike sports gear to make up for the boycott attempt.
He called the move by Nike a "calculated risk", and says it's one that will pay off because "even negative press is good press".
LeBron James, Chris Paul, and Kevin Durant were among the athletes that posted the ad on their Instagram accounts, which is a black and white image of Kaepernick along with the text "Believe in something".
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As the temperatures rose so did the tempers, with both players engaging in animated arguments with chair umpire James Keothavong. The biggest concern for Djokovic might well have been the conditions as the heat returned to NY after a few days of relief.
"Just bought a pair of nikes yesterday not knowing about this, but NOW I will be returning them!"
She added of his activism in general: "I think everyone has a choice to do what they choose to do".
"As much as I disagree with the Colin Kaepernick endorsement, in another way, I mean, I wouldn't have done it", Trump said. "The social justice issues that Colin and other professional athletes have raised deserve our attention and action".
"Having a huge company back him could be a controversial reason for this company, but they're not afraid".
In a series of tweets that continued Tuesday, Rich, who was also on "The Celebrity Apprentice", said he supported the right to protest, but that Nike lost his support when they endorsed Kaepernick.