"Having a huge company back him, could be a controversial reason for this company but they're not afraid and I feel like that was a really powerful statement to a lot of, a lot of other companies." Williams said on Tuesday at Flushing Meadows in New York.
Protesters burned Nike shoes and some consumers demanded a boycott after the footwear and apparel maker's unveiling of Kaepernick. The company's shares fell Tuesday, closing down 3.2 percent.
The former San Francisco 49er sparked a national controversy by kneeling during the national anthem to protest racial injustice and police brutality. He then opted out of his contract and was not offered a place on any team for the 2017 season.
He has since sued the NFL, accusing owners of colluding to blackball him and is still without a team, with a decision taken last month allowing him clearance to go to trial.
The story has attracted attention from many sides including criticism from President Donald Trump, who said in an interview to The Daily Caller that Nike's decision sends "a terrible message." However, Kaepernick has also won praise from elsewhere and has been honored by Amnesty International.
"He's done a lot for the African American community and it's cost him a lot and he continues to do the best that he can to support." Williams went on to say.
Nike's new advertising campaign, celebrating the 30th anniversary of its "Just Do It" slogan features Williams, as well as New York Giants wide receiver Odell Beckham Jr and Seattle Seahawks rookie linebacker Shaquem Griffin.