McNair made the comments during an NFL owner's meeting in 2017 while discussing the league's reaction to Colin Kaepernick's kneeling protest ... and said he was against "inmates running the prison."

When Hopkins heard about the comments, he was FURIOUS -- and now, he just opened up about the situation to GQ.

"I went home," Hopkins says ... "I ain't going to practice today. Hell no. I was about to not play in the game."

Hopkins also described his feelings when he heard the comments ... "It feels like I'm a slave again. Getting ran over. Listen to the master, go to work."

But, Hopkins says he took into consideration that McNair -- who died last year at age 81 -- was an "older" man and chalked up the comment to simple ignorance ... not aggressive racism.

"RIP, his soul. He was a good man, but some people they don't really ... When you grow up certain places, you talk a certain way."

"I try to take into consideration that he's done a lot of good for black people, so sh*t, you can't take nothing away from that."

Hopkins says he considered sitting out the Texans next game -- but ultimately decided to play because he didn't want to let his teammates down.

In the GQ article, DeAndre also vents about how upset he was that the Texans didn't give Colin Kaepernick a workout after starting QB Deshaun Watson suffered an injury during the 2017 season.

"Yeah, I was upset. Everybody needed to give Kaep a look. He can help a team win. I've seen a lot of quarterbacks that's not as good as Kaep, but teams don't want the heat behind them."