Golden State Warriors coach Steve Kerr says marijuana didn't help his chronic back pain, but he still thinks pro sports leagues must eventually reconsider their opposition to the drug. Kerr told CSN Bay Area that he experimented with marijuana a "few times" to help him cope with pain. Medicinal marijuana use has been legalized by the state of California, although it's still illegal under US federal law and against the rules for players in the NBA, NFL and Major League Baseball.