Rashard Mendenhall is walking away from the NFL. (Jeff Gross / Getty Images)

Rashard Mendenhall announced his retirement from the NFL on Sunday and the running back did it in the most unlikely way: with a thoughtful, eloquent column.

Mendenhall had two 1,000-yard seasons with the Pittsburgh Steelers before joining the Arizona Cardinals and was expected to become a free agent when the open period begins at 4 p.m. EDT Tuesday, but now he will quit, “grateful that I can walk away feeling as good as I did when I stepped into [the game].”

“[W]hen they ask me why I want to leave the NFL at the age of 26, I tell them that I’ve greatly enjoyed my time, but I no longer wish to put my body at risk for the sake of entertainment,” he wrote on Huffington Post. “I think about the rest of my life and I want to live it with much quality. And physically, I am grateful that I can walk away feeling as good as I did when I stepped into it. As for the question of what will I do now, with an entire life in front of me? I say to that, I will LIVE! I plan to live in a way that I never have before, and that is freely, able to fully be me, without the expectation of representing any league, club, shield or city.”

Mendenhall said he plans to travel and write and will relish being out of the modern spotlight that often brings all manner of hatred down upon athletes.

“Imagine having a job where you’re always on duty, and can never fully relax or you just may drown. Having to fight through waves and currents of praise and criticism, but mostly hate. I can’t even count how many times I’ve been called a ‘dumb [n-word]’. There is a bold coarseness you receive from non-supporters that seems to only exist on the Internet. However, even if you try to avoid these things completely — because I’ve tried — somehow they still reach you. If not first-hand, then through friends and loved ones who take to heart all that they read and hear. I’m not a terribly sensitive person, so this stuff never really bothered me. That was until I realized that it actually had an impact my career. Over my career, I would learn that everything people say behind these computer and smartphones actually shape the perception of you — the brand, the athlete and the person. Go figure!”

In his five seasons, Mendenhall writes that “the business of entertainment” has changed the game and the NFL.

“Today, game-day cameras follow the most popular players on teams; guys who dance after touchdowns are extolled on Dancing With the Starters; games are analyzed and brought to fans without any use of coaches tape; practice non-participants are reported throughout the week for predicted fantasy value; and success and failure for skill players is measured solely in stats and fantasy points. This is a very different model of football than the one I grew up with. My older brother coaches football at the high-school and youth level. One day he called me and said, ‘These kids don’t want to work hard. All they wanna do is look cool, celebrate after plays, and get more followers on Instagram!’ I told him that they might actually have it figured out.”