The NFL and the NFL Players Association have a staunch policy prohibiting marijuana use, but some players are asking them to reconsider it, saying pot can be used for pain relief, and possibly as concussion prevention.
If you play professional football, "your job automatically gives you the symptom of chronic pain," said Baltimore Ravens offensive tackle Eugene Monroe, who has played in the NFL since 2009. "You're hitting each other as hard as possible every single day in practice. Your body is in pain a lot of time."
More and more players are looking to marijuana for pain relief, he said, despite risking punishment from the NFL.
There are existing ways to manage pain: opioids and noninflammatory medications. But Monroe and other players are concerned about addiction and the potential for overdoses.
"All over our country people are addicted, and that's happening in our locker rooms," Monroe said.
Last year, a class action lawsuit was filed against the 32 NFL teams by former players who alleged that team coaches, staff members and doctors pushed painkillers onto players to get them back on the field. The case has been transferred to the federal court in the northern district of California. A similar suit was filed in 2014, but was dismissed.
During Super Bowl week, NFL Commissioner Roger Goodell said of the current marijuana policy, "It's an NFL policy and we believe it's the correct policy, for now, in the best interest of our players and the long-term health of our players."
Goodell acknowledged that there have been some scientific developments about the uses of marijuana, but not enough.
"I agree there has been changes, but not significant enough changes that our medical personnel have changed their view," he said. "Until they do, then I don't expect that we will change our view."
The NFL Players Association said, "Marijuana is currently a banned substance under the collectively bargained Substances of Abuse Policy. Both parties to the Policy (NFL and NFLPA) seek guidance from the independent medical professionals who administer the policy, and no change to marijuana's status as a banned substance has been recommended by those medical professionals."
But Monroe said it is time for more research to look at the possible benefits of medical marijuana, especially as he sees players turning to it. He's the first current NFL player to publicly take this stance.
"The NFL will need to have legitimate information before they remove marijuana from the banned substance list and ultimately not hurt their product in the field," Monroe said. "But there's opportunity in that space also, for the NFL to get involved and maybe lead efforts."
Some retired players admitted to using marijuana while in the NFL, and active players, such as Monroe, have said it's common. All the numbers regarding marijuana use in the NFL -- whether for pain relief, concussion prevention or recreation -- are anecdotal. Admitting to marijuana use could be career ending.
Nate Jackson, who retired after six seasons with the Denver Broncos, said he started using pot recreationally in high school, but began using it to manage pain on the field. Last year, he called on the NFL to reconsider its marijuana ban.
"Cannabis has been part of my football experience since I started," said Jackson, who played from 2003 to 2008. "I never liked the pills and medicated with cannabis."
Heather Jackson, one founder of the nonprofit Realm of Caring Foundation, said she knows of 19 current and former players who are using oil derived from the cannabis plant to lessen the impact of potential brain injuries when they are out on the field, and as a therapy after being hit with a concussion.
To get a better grasp of just how many players are using marijuana and why, Realm of Caring is raising money to help launch a study with Johns Hopkins University. Realm of Caring provides education and support about cannabis to adults and children suffering from a host of diseases, including epilepsy, cancer, multiple sclerosis and Parkinson's.
"We want to go in and learn as much about the players. Who's using? What kind of benefit? How does it benefit (players) versus traditional treatments? Are there other associated effects?" said Ryan Vandrey, an associate professor of psychiatry and behavioral sciences at Johns Hopkins Medicine.
Vandrey has been involved in cannabis research for 16 years. He also plans to do biological testing for "inflammatory biomarkers that have been associated with head trauma and pain."
With a large assessment of the players, Vandrey hopes that better studies can help researchers understand marijuana's impact on players.