MESA, AZ - As a fan watching a Mountain View High School freshman football game, you would see a fearless middle linebacker who looks opponents right in the eye.

But if you look a little closer, you’ll see something else. That middle linebacker is a girl.

With two blonde braids tucked into her shoulder pads, freshman Karstin Hollen goes out onto the field and shows the boys what she’s made of.

But this wasn’t a newfound love. Football was part of Hollen’s life since the day she was born.

“My brothers grew up playing football, and my dad coached it, and a few years ago I wanted to start playing but I just kind of procrastinated on it,” Hollen said. “Then last year I was like, ‘okay I actually want to play now.’”

Hollen has two older brothers, one whom is 20-years-old and plays for Scottsdale Community College. The other is 16-years-old and also plays for Mountain View.

Both of her brothers are also middle linebackers. “It’s kind of like a family thing now,” Hollen said.

Hollen said she loves that her whole family shares the same passion for football.

“I can really connect to my brothers, in a sense that they’re basically the reason I started playing football,” Hollen said. “So I think it’s cool cause they always give me tips after the game and I’ll take pictures with them and they’ll be like, ‘Dang my little sister is beating up all these boys.’”

Before Hollen started football, she wrestled for a while. But once she started flag football as a student at Stapley Junior High, she couldn’t resist. Hollen shared the moment that her flag football team realized she was more than just a girl without fear, but a real competitor.

Hollen said she was up against one of the best guys on the team, and she went to pull his flag and succeeded, even causing him to stumble. She said everyone just looked shocked, and ever since then she had earned a great amount of respect as an athlete.

However, it wasn't always easy.

Hollen said that when she first started playing on the feeder team for Mountain View last spring, there were many times that teammates made it hard on the aspiring trailblazer.

She recalled one day at practice, when a specific teammate wouldn’t stop picking on her. Hollen said the coaches weren’t on the field yet, and the teammate was repeatedly poking fun at her. Hollen said she went up to him and stood her ground, and told him she wasn’t going to take it from him anymore.

She said the whole team was shocked she had stood up to him, and by the end of practice the teammate came up to her and apologized. After she asserted herself, the teasing stopped.

“That was when they realized you can’t mess with me,” Hollen said with a smile.

After playing flag football, Hollen made the choice to play tackle. Taylor Elias, Hollen’s best friend, recalled the girls’ reactions to Hollen joining the team.

“I know a lot of my cheer friends were thinking that it is so cool that a girl is actually on this team and not afraid to get tackled by a guy,” Elias said. “I was very proud, honestly, just to even call her my friend.”

Hollen said that rival teams notice she’s a girl once they hear her voice, and are initially taken aback.

“They would sometimes treat me differently, say things like ‘Go easy on her,’ until I tackled them then they were (now saying) ‘Okay, guys block her,'” Hollen said with her chin held high.

Hollen reflected on the exhausting 6 a.m. workouts on school days, where a lot of her teammates felt like quitting, and sometimes she did too. But Hollen knew she had to prove them wrong.

“They can’t say ‘Oh, we’re so much tougher than girls,’ because I can do it too."

Ryan Wood, a freshman defensive end on Hollen’s team, said opposing teams sometimes stereotype Hollen before facing her on the field.

“Other teams don’t know her work effort and what she’s done, so they go out there and underestimate her,” Wood said.

Wood said that once she gets out there and plays, she proves them wrong.

“We all accept her, we all take her, she’s a great part of the team,” Wood said.

Elias added, “This isn’t just a guy sport. Karstin proved us all wrong.”