Cleveland Cavaliers star LeBron James is the latest athlete to speak out about Colin Kaepernick's national anthem protest and why he's not been signed by an NFL team.

"I don't represent the NFL, I don't know their rules and regulations," James told reporters after Cleveland's practice on Sunday. "But I do know (Kaaepernick) is getting a wrong doing, I do know that. Just watching, he's an NFL player."   

After a string of injuries to starting quarterbacks, there has been debate as to why Kaepernick has remained unsigned. 

Kaepernick started sitting for the American national anthem last season, when he was a starter for the San Francisco 49ers, to protest against police brutality But after meeting with Green Beret Nate Boyer, Kaepernick decide to kneel instead of sit and many players followed his lead. 

"I am not going to stand up and show pride in a flag for a country that opresses black people and people of colour," Kaepernick said in an interview with NFL media last summer. "To me, this is bigger than football and it would be selfish on my part to look the other way." 

"It just feels like he's been blackballed out of the NFL," James said. "So I definitely don't respect that." 

James also compared Kaepernick's movement to civil right leaders Martin Luther King Jr. and Muhammed Ali. 

"Obviously (Kaepernick) had a vision like Martin Luther King and like some of our all-time greats, that people couldn't see further than what they were doing at the point and time."

Kaepernick has filed a grevience against the NFL claiming owners have colluded to keep him unsigned.