A retired football player told me in 2005 that “no one walks away from the NFL. We only limp or are carried off.” The very few exceptions to that rule—those who left the game on their own terms, like Jim Brown or Barry Sanders—were considered legends for having the courage to say good-bye.

In recent years that perception has changed slightly as some players, with years left on their odometer—Chris Borland, D’Brickashaw Ferguson, and Hussain Abdullah come to mind—have opted for early retirement. This mini-wave of younger retirees is motivated by the science we now have about concussions and the acknowledged effects that the sport can have on the brain.

This past weekend, however, early retirement was taken to another level as Buffalo Bills cornerback Vontae Davis retired… at halftime. In a move that has shocked and roiled the NFL, the 10-year veteran just walked away from his hapless team after the second quarter, with the Bills down 28-6 to the Los Angeles Chargers. He got dressed in his street clothes during halftime and left the stadium. Then, after the game ended, Davis posted a statement on Instagram. He wrote,

“This isn’t how I pictured retiring from the NFL.

But in my 10th NFL season, I’ve been doing what my body has been programmed to do: Get ready to play on game day. I’ve endured multiple surgeries and played through many different injuries throughout my career and, over the last few weeks, this was the latest physical challenge.

But today on the field, reality hit me fast and hard: I shouldn’t be out there anymore.

I meant no disrespect to my teammates and coaches. But I hold myself to a standard. Mentally I always expect myself to play at a high level. But physically, I know today that isn’t possible, and I had an honest moment with myself. While I was on the field, I just didn’t feel right, and I told the coaches, ‘I’m not feeling like myself.’

I also wondered: Do I want to keep sacrificing?

And truthfully, I do not because the season is long, and it’s more important for me and my family to walk away healthy than to willfully embrace the warrior mentality and limp away too late. [Emphasis added.]

This was an overwhelming decision, but I’m at peace with myself and my family. I choose to be grateful to God for allowing me to play the game that I have loved as a boy until I turned 30 years old. I choose to be grateful to God for being part of the NFL and making lifelong friends over the last decade. There were roadblocks and pitfalls along the way, but I am grateful to God for all of it because he doesn’t promise any of us an easy journey.

Lastly, I am grateful to God for what he has in store for me ahead, in this next chapter of my life.”

By walking away from the game, it must be noted, Davis also said goodbye to the $4 million he was due to be paid for the rest of the season. Immediately, the condemnations started flying across the football world. Former coach Rex Ryan thundered, “This is a joke, you don’t quit.”

Another ESPN commentator, Damien Woody said, “There is nothing funny about this. My blood is boiling. I want to fight this guy right now.” Woody also called it “a punk move.… What kind of punk does stuff like that?” His teammate Rafael Bush said after the game, “I think I did lose a little respect for him as a man.”

Manhood in the NFL is defined by a willingness to get hurt and hurt others, even if your heart isn’t in it. This is what Davis called “the warrior mentality.” In the eyes of the NFL, he broke a sacred code. But perhaps, knowing that this kind of criticism would be coming, it took a particular kind of courage for Davis to walk away when he did. How many others would have this kind of bravery knowing this fusillade of criticism was right around the corner?

As former NFL executive Andrew Brandt tweeted, “[Davis] retired willfully, albeit with poor timing. The vast majority of NFL players are involuntarily ‘retired’ before they want to do so willingly.” Hall of Fame Wide Receiver Cris Carter perhaps said it best, and with a measure of charity, “There ain’t no easy way to get out of this business.”

That last word is critical. These aren’t “warriors.” This is a business—a business that has shown the potential to rob those who play it of their joints, their nerves, or their minds. If a player does not feel like they are in a position to go out there with a degree of focus, they are not only poised to hurt their team; they can hurt themselves in a way that holds no prospect for recovery. As Vontae Davis said in his statement, “I shouldn’t be out there anymore.” That’s all anyone should need to hear.