Adrian Peterson, the Minnesota Vikings All-Pro running back, “went there,” and now there’s no going back. In a moment of supreme frustration with NFL owners and their lust for the lockout, Peterson said, “It’s modern-day slavery, you know?”

For sportswriters inclined to cozy up to Commissioner Roger Goodell, Peterson’s words were manna from heaven. He’s been called “ungrateful,” “out of touch,” “an idiot” and, in the darker recesses of the blogosphere, far worse. Even those inclined to openly sympathize with the players have stated their “great offense” that Peterson could liken his situation to the horrors of chattel slavery. As Jamil Smith, a very righteous producer at the Rachel Maddow Show, tweeted to me, “I want to hear Adrian Peterson out. I just need him to know that using ‘slavery’ makes it harder for me to hear him.” Fellow players, Ryan Grant and Heath Evans, also took exception, with Grant calling it “a very misinformed statement.”

It’s not difficult to understand why some are crushing Adrian Peterson for likening his glamorized career to “modern-day slavery.” But all the criticism in the world doesn’t explain why the metaphor would cross his mind in the first place. It doesn’t explain why other athletes—Curt Flood, Larry Johnson and Warren Sapp among them—have reached to this explosive analogy as a way to articulate their frustrations.

At least two books have already been written that explore this concept: 40 Million Dollar Slaves, by NY Times columnist William Rhoden, and The Slave Side of Sunday, by former NFL player Anthony Prior. Both are stunning testaments to the fact that there is more here than meets the eye. Even if we are repelled by Peterson’s choice of words, it’s worth putting down the torches and trying to understand why this is the analogy that just won’t die, especially in the world of pro football.

To be an African American NFL player is to play in a league where 70% of the players are black and 100% of the owners are white. It’s a league where only 3 percent of head coaches were black until the famous (or infamous) lawyer Johnnie Cochran threatened a mass class-action lawsuit, saying he would “litigate if they do not integrate.” It’s a league where collegiate players hoping to be drafted show up to the NFL combine to be poked, prodded and have various body parts judged and measured. Teams basically do everything short of having someone run their finger along the players’ gums. If you are lucky enough to make the league, you will be blessed with a career that will, on average, last 3.4 years, and cursed with a life expectancy twenty-two years shorter than that of the typical American male. Your contract isn’t guaranteed, so if you do sustain some horrific injury, you are officially yesterday’s trash.

I interviewed former NFL player and Slave Side of Sunday author Anthony Prior several years ago, and this is what he said about the player as slave metaphor: “Black players have created a billion-dollar market but have no voice in the industry, no power. That sounds an awful lot like slavery to me. On plantations slaves were respected for their physical skills but were given no respect as thinking beings. On the football field, we are treated as what appears like gods, but in fact this is just the ‘show and tell’ of the management for their spectators. In reality, what is transpiring is that black athletes are being treated with disrespect and degradation. As soon as we take off that uniform, behind the dressing room doors, we are less than human. We are bought and sold. Traded and drafted, like our ancestors, and the public views this as a sport, ironically the same attitude as people had in the slavery era.”

Prior contended that coaches and other authority figures in the game use racism to bully African-American players in an effort to instill obedience. “I’ve heard coaches call players ‘boy,’ ‘porch monkeys,”sambos,’ ” he said. “Players don’t get tested on their athleticism as much as they get tested on their manhood.

“The intimidation is immense…. I’ve seen players benched because a coach saw them with a white woman, or overheard a criticism of his incompetence, or because a player didn’t go to Bible study. I’ve been in film sessions where coaches would try to get a rise out of players by calling them ‘boy’ or ‘Jemima,’ and players are so conditioned to not jeopardize their place, they just take it.”

What is so bracing about this moment in NFL history is that players aren’t “just taking it” anymore. Attacking Adrian Peterson for using “the s word” is pure distraction from what’s taking place in front of our eyes. Players are demanding to see the owners’ financial ledgers, to choose their own doctors and, for the first time in NFL history, to be treated like fully grown men. It’s remarkable that these twenty-first-century gladiators are praised by the media when they show so-called “manhood” on the field by playing through pain, but derided when they refuse to be treated like children.

Curt Flood, who by 1971 had sacrificed his all-star career in the fight for free agency, once said, “A well-paid slave is nonetheless a slave.” He was excoriated for that statement and inexcusably run out of his sport. Hopefully we can do a little better this time around. Hopefully we can hear the frustration beneath the words.