Basketball legend Kareem Abdul-Jabbar weighed in on the controversy surrounding Colin Kaepernick's decision to sit during the national anthem, in an op-ed published today in The Washington Post, portraying his protest as "highly patriotic."

"What should horrify Americans is not Kaepernick’s choice to remain seated during the national anthem, but that nearly 50 years after [Muhammad] Ali was banned from boxing for his stance and Tommie Smith and John Carlos’s raised fists caused public ostracization and numerous death threats, we still need to call attention to the same racial inequities," Abdul-Jabbar wrote, referring to prominent protests by black athletes that were once considered controversial but have since become iconic symbols of the U.S. civil rights movement.

Abdul-Jabbar's defense of Kaepernick comes amid growing backlash against the quarterback's actions.

Republican presidential nominee Donald Trump said Monday that "maybe [Kaepernick] should find a country that works better for him," and fans posted videos of themselves burning Kaepernick jerseys and other memorabilia on social media.

Abdul-Jabbar — an NBA Hall of Fame center who played for the Milwaukee Bucks and Los Angeles Lakers and holds the league record for points scored, blocks and MVP awards — certainly adds prestige to those defending Kaepernick's protest.

A homemade Colin Kaepernick shirt burns in a video posted to YouTube on Aug. 27, 2016 titled, "49ers Colin Kaepernick Jersey Burning!!"(JohnnyOncomingStorm/YouTube) A homemade Colin Kaepernick shirt burns in a video posted to YouTube on Aug. 27, 2016 titled, "49ers Colin Kaepernick Jersey Burning!!"

Previously, Kaepernick's most vocal defenders were activists like Black Lives Matter advocate and New York Daily News columnist Shaun King.

The retired NBA star, 69, noted in his piece the financial risk that Kaepernick took by speaking up for his beliefs and compared him to Army Reserve 2nd Lt. Sam Kendricks, who, while competing in the Rio Olympics, stopped short while pole vaulting to honor the national anthem.

Abdul-Jabbar wrote that both athletes made a sacrifice.

"What makes an act truly patriotic and not just lip-service is when it involves personal risk or sacrifice. Both Kendricks and Kaepernick chose to express their patriotism publicly because they felt that inspiring others was more important than the personal cost," he said.

He portrayed the matter as a nonpartisan issue, suggesting that a discussion around Kaepernick comes amid "Trump and [Hillary] Clinton supporters each righteously claiming ownership of the 'most patriotic' label."

Abdul-Jabbar is no stranger to commenting on political matters and is widely regarded as liberal. He regularly contributes opinion pieces on issues of race and religion to The Washington Post and The Huffington Post.

He disappointed some progressives by endorsing Clinton before the New York primary in April in an op-ed for The Washington Post in which he praised Sanders' "dedication to the welfare of all Americans" but said he preferred Clinton, whom he called a proven warrior."

Bill Russell, left, Cassius Clay and Lew Alcindor, later Kareem Abdul-Jabbar, speak at a press conference rejecting US Army induction, June 1967.(Bettmann Archive/GettyImages) Bill Russell, left, Cassius Clay and Lew Alcindor, later Kareem Abdul-Jabbar, speak at a press conference rejecting US Army induction, June 1967.

Abdul-Jabbar was born in New York City and emerged as a high school basketball star there.

In 1967, Abdul-Jabbar, then known as Lew Alcindor, participated in what is known as the Ali summit, a news conference lending support to Ali's rejection of his military induction and conscientious objection to the Vietnam War.

NBA legend Bill Russell and NFL star Jim Brown were among the news conference's other notable attendees.

New York Knicks star Carmelo Anthony referred to Ali in an Instagram post in July, after the police shooting deaths of Alton Sterling and Philando Castile, calling for fellow athletes to "step up" and "demand change."