No one will dispute Jason Kelce is as tough as they come.

He spent 13 years in the NFL, all as a starter, and played center, one of the most physically punishing positions there is. He took the lead on the Brotherly Shove, which means any time the Philadelphia Eagles ran their patented short-yardage play, he was the guy at the bottom of a two-ton-plus pile of humanity.

So no, no one will ever say Kelce is soft or question his “manliness.” Whatever that means.

But while Kelce’s grit makes him revered in Philadelphia and respected around the league, it’s his willingness to be vulnerable that resonates beyond his sport.

Showing emotion has long been equated with weakness for men, particularly in sports, and there are some Americans doubling down on the idea that being an unfeeling "alpha male" is a selling point. Kelce and his younger brother Travis have flipped that notion on its head with their unabashed willingness to be open with their feelings, and the message is a powerful one — for boys and young men, especially.

You can cry in public, as Kelce did Monday night when it was clear his NFL career was coming to an end. You can tell your brother you love him, as both Kelces often do. You can voice your fears about yourself and your future, as Kelce did in his excellent documentary chronicling his internal debate over retirement. You can gush about your wife and your kids and your parents.

And none of it diminishes you in the least.

"For me, the Kelce brothers represent a kind of authenticity around masculinity and manhood that is a really important counterpoint to the cartoon version of the strong men that exists in so many parts of our culture," said Cheryl Cooky, a professor at Purdue University who studies the intersection of gender, sport and culture.

"Some folks see that kind of `alpha male' stereotype out there and they’re invested in it. And our culture invests in ... the notion that being a real man comes with dominance and disparaging your opponent and ostracizing anything other than the idealized version of masculinity," added Cooky, author of Serving Equality: Feminism, Media and Women’s Sports.

"The Kelce brothers demonstrate there are other ways of being a man. The fact they have the kind of popularity and audience they have indicates there’s pretty large segment of our society that wants to see that and is supportive of that."

Kelce is not the first athlete to be free with his feelings. There have been others who've expressed their most heartfelt emotions without apology or fear for what others might think, with LeBron James immediately coming to mind.

But few have done so as consistently, as authentically and as publicly as Kelce.

The Kelce Brothers have become like honorary family members or permanent houseguests for many Americans with as omnipresent as they've been the last year. They were already both wildly popular in the cities they played in, Jason in Philadelphia, Travis in Kansas City. Wildly successful, too, Super Bowl champions who are each considered the best at his position.

Their reach broadened last season with the launch of their "New Heights" podcast, and became stratospheric when their teams made the Super Bowl. It was the first time brothers had faced off in the Super Bowl, and the Kelces and their mother, Donna, were everywhere.

Still are, thanks to Travis' high-profile romance with girlfriend Taylor Swift.

But what has made the Kelces so appealing, Jason in particular, is the authenticity with which they support and celebrate one another. Travis never misses the chance to thank Jason for helping him get back on the right track in college, even revealing last year that he wears No. 87 because it's the year his brother was born. Jason chokes up when he expresses his pride at the man his brother has become.

When the two met on the field after last year's Super Bowl, there wasn't trash talking or ribbing. They congratulated one another and said they loved the other. When Donna Kelce found her oldest son, he buried his face in her shoulder briefly and let the tears come, then told her to go celebrate with Travis Kelce and the Chiefs.

All of this unfolded on national TV. And it didn't bother them in the slightest because emotions, on and off the field, are not something to be ashamed of. Neither is letting others see them.

Jason Kelce endeared himself to Eagles fans with his NSFW speech at Philadelphia's Super Bowl parade in 2018. But he was just as raw in his documentary, "Kelce," which shows him wrestling with the decision last season of whether or not to retire.

“I have no doubt I can be a loving father. I have no doubt that I can be successful. But where am I gonna get that?” he asks, breaking down. “Where am I gonna be the best in the world at what I (expletive) do and not because of anything other than I go out there and earned it?”

For anyone who has ever silently struggled with our self-worth or doubted our capabilities — in other words, all of us — it was an incredibly relatable moment. As was his recognition he'd let his wife down by joining his brother for an appearance on "Saturday Night Live" just days after his third daughter was born.

"Well, that went great," he said after a terse phone call with wife Kylie. "Yeah. Not up for Dad of the Year right now. Or Husband of the Year."

So many celebrities — heck, so many people — curate their lives these days to make it seem as if they're perfect, secreting away the blemishes and the sorrows and the disappointments. The NFL has traditionally taken it even further, prizing players for appearing impervious to pain — physical and psychological — and emotion.

That's not real life, however, and pretending it is causes real harm. But when one of the most rugged players in the NFL shows his feelings and embraces his full humanity, Kelce gives people watching him permission to do the same.

"It's a really important shift we're seeing," Cooky said. "(With Kelce), we're seeing this version of manhood, this version of brotherhood, this version of an NFL player, this version of a husband and a father that is really challenging that old-school masculinity."

Jason Kelce is a first-ballot Hall of Famer, as tough an NFL player as you'll find. He also cries freely and loves openly. There doesn't have to be a contradiction between those two personas and, as he retires, Kelce should also be celebrated for showing us that.

Follow USA TODAY Sports columnist Nancy Armour on social media @nrarmour.

This article originally appeared on USA TODAY: Eagles star Jason Kelce gave us all the feels as he ends career