LOS ANGELES — Staying in shape is almost second nature to Derrick Malone Jr., a former University of Oregon star linebacker with an impressive resume.

Malone won two Rose Bowl trophies and came close to a National Championship, all while playing through injuries, and even made it to the NFL. But when he dislocated his shoulder in his first year training with the Atlanta Falcons, it was hard to face the fact that his dream career was over.

“Something that was going through my mind was, 'I'm a man. I play football. I have to have this grit to myself,'" he said.

When accustomed to being one of the hardest hitters on the field, the uncertainty of a future after football was a direct hit to Malone's mental health. He hit rock bottom and wrote a blog, "Depression, I deal with it too." For the first time, he expressed his battle with mental health and depression.

Through journaling, Malone hatched the idea for his first children’s book, "Why Don't Big Boys Cry?" The main character, Kobe, is biracial, Mexican and Black, like the community in San Bernardino where Malone grew up.

In the story, when Kobe’s mom tells him they’re heading across the country, he doesn’t know how to adjust to the changes coming his way.

“[Kobe] is bottling everything in and not allowing himself to cry because, in his mind, big boys don't cry,” Malone said.

In some ways, Malone can relate. His first memories of depression go back to his childhood when his parents divorced. Studies show that 50% of the time, mental illness begins by the age 14. But only half of the kids in the U.S. struggling with mental health actually receive treatment.

Malone, therefore, hopes his book will help young boys in particular know it’s OK to admit when you’re not OK.

"This [book] is also a tool to spark a new conversation that may be uncomfortable for the child and the parent," he said.

Malone's goal as a mental health advocate is to remove the stigma of mental health and give power to vulnerability.