AB fired off the explosive comments in a sit-down interview with Naji of "Cigar Talk" ... ripping the guy for settling his past lawsuit with the NFL, saying he doesn't believe Kaepernick actually wants to play still, and openly wondering if the 34-year-old's community contributions have actually made a difference.

Brown's rant all began after he appeared to be puzzled about why people feel bad for Kaepernick these days ... saying he thinks the settlement Kap reached with the NFL in 2019 following his collusion lawsuit sufficiently took care of him.

"He took a deal," Brown said. "We don't feel sorry for you. You took the deal. F*** outta here."

"'Oh, Kaepernick!'" he added in a mocking tone. "Man, you on f***ing Nike, man. F*** outta here."

Brown then said he thinks Kaepernick "don't want to play" football anymore ... and said even if the former 49ers star still truly did, he called his skill set "trash."

"All that is cap," Brown said. "We ain't respecting that, bro. You took the money, the commercials. We don't see you outside. We don't see him in the hood. He don't do nothing. Like, we cool. But, nah, we ain't even stan Kaepernick."

Brown continued, "He not even from the hood. He haven't even been in the trenches. We like Kaepernick and all, but we ain't really on that."

AB went on to wonder out loud how much Kaepernick has really done for those in need.

"He built a foundation," Brown said. "What it do, though? I'm being real. What superhero he enforce? Who he put on? Who he help?"

Of course, Kaepernick has been heavily involved in charitable work since becoming an NFL free agent following the 2016 season ... he created the "Know Your Rights Camp" to help in the fight for social justice. He also famously donated $1 million to orgs with similar calls for action. Kaepernick even wrote a children's book.

As for his playing career, Kaepernick has said over and over again he wants to get another crack at playing in the league -- and has been working out like a mad man in order to get a tryout somewhere.