The demands of their 162-game season grinds down Major League Baseball players, often turning nagging injuries into chronic ailments. But there is no provision in MLB’s collective bargaining agreement with the players to allow use of marijuana for medicinal reasons.

That frustrates agent Joshua Kusnick, who represents Jeremy Jeffress, a pitcher with the Toronto Blue Jays. Jeffress suffers from epilepsy. The seizures from that disease nearly ruined his career and could have cost him his life, until he discovered that marijuana helped him control his condition. He has since found another medication that has proved effective.

“Had Jeremy not been able to use a suitable medication, the outcome would have been for us to pursue legal action,” Kusnick said. “Basically, if he couldn’t have found something other than pot to control his seizures, baseball would have said ‘too bad.’ Which is insane, because this was ultimately not a lifestyle decision by Jeremy. It was a life decision.”

Jeffress’ case is complex. He entered pro baseball at age 18 after graduating from high school in South Boston, Va., and quickly ran into trouble for his marijuana use. When he first tested positive for marijuana, he underwent a counseling program for first-time offenders. In 2007, while pitching in the minor leagues, he tested positive again and was suspended 50 games. Two years later, a third positive test resulted in a 100-game suspension.

During the time he was struggling to stay on the field, Jeffress began having seizures and discovered that smoking marijuana was the one thing that gave him relief. When he quit smoking marijuana, the seizures returned. “The doctors have told him that the correlation between not smoking marijuana and having the seizures was a real one,” Kusnick said.

Jeffress eventually quit smoking cannabis and turned to another medication to control his seizures. If he had been unable to find an effective medication, and had he continued to smoke marijuana and failed another drug test, he could have been thrown out of baseball for good.

For some people seeking relief from pain and seizures, Marinol (dronabinol), an FDA-approved drug, has been marketed as a safe alternative to medicinal marijuana. But it was not an option for Jeffress because it remains on baseball’s list of banned substances.

“No one is ever going to sue for the right just to smoke marijuana, because of the public perception, in my opinion,” Kusnick said. “But if somebody had a medical reason for using it, like this, that’s where I think (MLB) and the JDA (joint drug agreement) would be screwed.”

Using marijuana for medical reasons is legal in 20 states and the District of Columbia. Retail sales of recreational marijuana become legal in Colorado on Wednesday, but MLB Players Association spokesman Greg Bouris said there are no plans for baseball to alter its drug policy. That inflexibility leaves Kusnick angry.

“I’ve been told by multiple doctors that they are furious at the way the rules are set up because they have an inability to prescribe their treatment,” he said. “It shouldn’t be dictated by the JDA. The medical profession is hampered by the JDA, and that’s horrible.”

Updated Jan. 2 at 10:45 a.m. The following corrected information has been added to this article: Because of a reporter’s error, it was incorrectly reported that Jeffress had used Marinol, when in fact he used another medication to control his seizures.