Free-agent offensive tackle Eugene Monroe announced his retirement from the NFL on Thursday.
"After 18 years, I am retiring from the game I love," Monroe said in a statement. "This was not an easy decision to make, but I know it's the right one for me, my health and my family. Thank you to my fans for your continued support, and to my friends and family for always standing by me. I'm excited about what's to come."
Monroe discussed his decision further in a post on The Players' Tribune.
"The last 18 years have been full of traumatic injuries to both my head and my body," he wrote. "I'm not complaining, just stating a fact. Has the damage to my brain already been done? Do I have CTE? I hope I don't, but over 90% of the brains of former NFL players that have been examined showed signs of the disease. I am terrified.
"That's why one of the first things I'm planning to do is to go to the doctor. I need to take stock of my current health, and I don't want to miss a thing. I'm going to get brain and body imaging scans, mental health assessments -- anything that might help me get a handle on the state of my body and my mind. My health is critical to the future of my family."
Monroe, 29, was released by the Baltimore Ravens in June. An outspoken supporter of medical marijuana, he told The New York Times after his release that he wondered whether his advocacy contributed to his release.
The only active player to publicly support taking marijuana off the NFL's banned substances list, Monroe said in a statement last month that he had no plans to end his campaign.
"Despite the current uncertainties, one thing is for sure: Whatever happens in terms of my professional football career, I will never stop pushing for the League to accept medical cannabis as a viable option for pain management," he said.
The New York Giants reportedly showed interest in Monroe, as did a few other teams, but Monroe said he will now take the same energy he put into his football career and use it in the next phase of his life.
"The game of football has helped me to know what it takes to set objectives, to know how to work tirelessly to achieve them and to push through any obstacle no matter how insurmountable it may seem," he said. "For all my anxiety, I'm actually excited for what the future holds because I feel prepared for it."
Monroe started only 17 games in two seasons since receiving $17.5 million in guaranteed money as part of the five-year, $37.5 million deal he signed with the Ravens in 2014. He missed time because of four injuries since the start of the 2014 season: knee (four games), ankle (three), concussion (three) and shoulder (two).