"I am hopeful that I'll be able to keep playing football," James told Steve Politi of NJ.com. "It is a game that I love very dearly. I know right now I'm doing something that makes some people uncomfortable, and that I'm going against the establishment to push for a change in the way they look at this medicine. I know there's a greater purpose here for a lot of guys in this league who I consider family members."
James, 27, spent the entire 2017 season on injured reserve with a concussion. He was on the Detroit Lions' roster but did not play after August.
Marijuana is on the NFL's banned substances list. Repeated positive tests can lead to suspensions or expulsions from the league. James has never been suspended for a positive test.
NFL commissioner Roger Goodell has been pessimistic about the use of marijuana.
"I think you still have to look at a lot of aspects of marijuana use," Goodell said on Mike and Mike in 2017 (h/t Los Angeles Times). "Is it something that can be negative to the health of our players? Listen, you're ingesting smoke, so that's not usually a very positive thing that people would say. It does have an addictive nature. There are a lot of compounds in marijuana that may not be healthy for the players long term. All of those things have to be considered."
James said he wants to be known as a pioneer for marijuana use in the NFL as a painkiller.
"I hear it all the time from retired players who say, 'I was so scared to say something when I was playing,'" James said. "We are the engine that drives this league. If we can't get onto the field with a less harmful medicine and we can't live our life after football, how are we going to tell our kids to play this game?"