Miller, a fourth-year player for the Buckeyes, said he had notified head coach Ryan Day of his suicidal thoughts and Day immediately put him in touch with medical professionals to seek help.
Miller had been absent from this year's spring practices and was deemed unavailable a few days ago without explanation. He shared the reasoning behind the decision to retire in a detailed statement on social media.
"I would not usually share such information. However, because I have played football, I am no longer afforded the privilege of privacy, so I will share my story briefly before more articles continue to ask, 'What is wrong with Harry Miller,'" his statement read. "That is a good question. It is a good enough question for me not to know the answer, though I have asked it often."
After meeting with medical professionals, Miller said he tried going back to football while covering up the scars on his wrists and throat with tape.
"At the time, I would rather be dead than a coward. I'd rather be nothing at all, than have to explain everything that was wrong," he said. "I was planning on being reduced to my initials on a back of a helmet. I had seen people seek help before. I had seen the age-old adage of how our generation was softening by the second, but I can tell you my skin was tough."
Miller, a student in the Ohio State college of engineering with a 4.0 GPA, will continue his studies. He said in the statement that Day is also finding a way for Miller to help other players in the program who might be addressing mental health.
"I hope athletic departments around the country do the same," Miller said. "If not for [Day] and the staff, my words would not be a reflection. They would be evidence in a post-mortem."