(CBS) Former Bears quarterback Jim McMahon has been open about his usage of medical marijuana to assist the pain that a 15-year NFL career has wrought on him. Now, McMahon is pushing for marijuana legalization.

McMahon has joined the likes of Ricky Williams and other former athletes to voice for legalization. On Sunday, he spoke at the Southwest Cannabis Conference in Texas, joining Williams and former defensive end Marvin Washington, speaking to how marijuana has helped him deal with post-football pain.

“I have arthritis pretty much in all my joints,” McMahon told the Star-Telegram before the roundtable discussion. “My head problems have been pretty severe at times. (Marijuana) makes all that pain go away. I just forget about the pain.”

Speaking at the conference, McMahon suggested that former Bears coach Mike Ditka knew his team had players smoking cannabis.

“Mike Ditka would say, ‘Oh, all you guys, you pot smokers,'” McMahon said. “That’s what he’d call us. ‘You pot smokers.’ We’d say, ‘It’s better than being drunk out here. We’re still functioning.'”

McMahon played in Chicago from 1982-’88, quarterbacking the Bears to victory in Super Bowl XX. His last season came in 1996 with the Packers.

Now 56, McMahon battles early stages of dementia and believes he has CTE.

McMahon said that he smokes during the morning and at night to help him sleep. He smokes a specialty marijuana to aide his physical pain and also consumes edibles.

Now, McMahon’s part of a panel fighting for marijuana’s legalization.