Justine Siegal envisions a future where no girl ever has to hear the words she’s been told thousands of times before.

Girls can’t play baseball.

When are you switching to softball?

You should quit.

Had Siegal given up on her love for baseball when first hearing those words at the age of 13, she might never have become the pioneer in the sport that she is now.

She instead turned those words into motivation as she embarked on a number of firsts: the first woman to coach for a professional men’s baseball team (Brockton Rox, 2009); the first woman to throw batting practice to an MLB team (Guardians, 2011); the first woman to coach for a Major League organization (Athletics, 2015).

It’s obvious Siegal has had her success. Some people keep things like that -- the knowledge they gained through the process -- to themselves. But Siegal wanted to share it. She knew what she was doing was bigger than baseball.

“Why wouldn't you want others to have a better experience than you did? Why wouldn't you want to build for those girls and boys that are behind you?” Siegal said in a phone interview with MLB.com. “I was the first woman to coach in a Major League Baseball organization and now there's over a dozen women coaching pro ball. I always knew that I would be the one banging my head against the wall so that others could go through.”

In an effort to help forge a path for people like Alyssa Nakken and Kelsie Whitmore and other like them, Siegal founded Baseball For All -- a nonprofit organization that hosts the largest girls’ baseball tournament in the country -- in 2015, with a mission to build gender equity in baseball by providing girls with opportunities to play, coach and lead in the sport.

The seventh BFA Nationals tournament took place over the weekend in Mesa, Ariz., with more than 400 players ages 6-16 from 30 states and three countries in attendance. This year, in partnership with the D-backs and Athletics, the Opening Ceremonies were held at Hohokam Stadium -- home of A’s Spring Training -- and the players were honored during a pregame parade on Sunday at Chase Field. Maybelle Blair, an original All-American Girls Professional Baseball League player and regular attendee of BFA events, as well as MLB girls baseball tournaments, threw out the first pitch.

Siegal remembers holding back tears at the sight of the inaugural BFA Nationals tournament after the first one she held. She had never seen so many female baseball players in one place, and watching them line up for the Opening Ceremonies was a moment that still tugs on her heartstrings, even seven years later.

Throughout the weekend, not only did participants get to compete alongside hundreds of other girls just like them, but they had the chance to meet Blair and Cubs MiLB hitting coach Rachel Folden.

Seeing and hearing from women in baseball was important, Siegal said, because girls need to know that they can play baseball, too.

“As a woman, even as a girl, you would love it to be just about baseball,” she said. “But the fact is that when you walk on the field and everybody stares at you and everyone has an opinion of whether you should be there, it becomes much more.

“Whether that's Kelsie [Whitmore] playing in the Atlantic League, Alyssa [Nakken] representing in the Major Leagues, or the 400-plus girls here that go into their hometown leagues -- they know that as much as they love baseball, they also have to represent that girls and women belong in the game, a responsibility that boys and men do not have.”