Colin Kaepernick takes shot at NFL, says he hasn't 'seen any substantial change' since he last played

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Colin Kaepernick has not played in the NFL since the 2016 season, when he created a firestorm when he kneeled for the national anthem to protest what he believed are racial injustices in the U.S.

Since then, Kaepernick has been at the forefront of social activism, calling for the abolishment of the police and prisons as well as likening the NFL Draft to a slave auction. He accused NFL owners of blackballing him from the league, and after the two sides settled, his two tryouts in front of scouts failed to yield a contract with a team.

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San Francisco 49ers quarterback Colin Kaepernick, #7, flexes his muscles after scoring a touchdown during their 45-31 victory over Green Bay Packers in their NFC Divisional playoff game Saturday, Jan. 11, 2013 at Candlestick Park in San Francisco. (RICK WOOD/MILWAUKEE JOURNAL SENTNEL / USA TODAY NETWORK)

The former San Francisco 49ers star, who led the team to a Super Bowl appearance during the 2013 season, released a graphic novel taking readers through the senior year of high school as he decides whether he wants to continue to play football in college or take a chance at Major League Baseball.

In an interview with NPR on Tuesday, host Juana Summers mentioned to Kaepernick about the last page in the book, where he is seen taking a knee and asked whether he thought the NFL had "changed for the better" since he last played a football game in January 2017.

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San Francisco 49ers quarterback Colin Kaepernick, #7, looks on prior to the game against