NFL Commissioner Roger Goodell is leaving the door open on medical marijuana use for pro football players.

Although it’s been legal to buy and use marijuana in Colorado since Jan. 1, smoking marijuana is still illegal under the NFL’s collective bargaining agreement.

When asked if a player might ever be allowed to use medical marijuana in states where it’s legal, Goodell told ESPN.com he could envision a time when players use medical marijuana in states where it’s legal.

"I don't know what's going to develop as far as the next opportunity for medicine to evolve and to help either deal with pain or help deal with injuries, but we will continue to support the evolution of medicine," he said.

He said he could envision a time when players use medical marijuana in states where it’s legal.

His remarks were the first comments in the league about marijuana since 2012, when Washington and Colorado voted to legalize pot.

Goodell also addressed the Jonathan Martin bullying case, concussions in the game and whether the NFL was ready for an openly gay player.

On the latter, he said: "Yes. There may be, I don't know, but the answer to that is yes."

Last week, Goodell also said he hasn’t ruled out a Super Bowl taking place overseas.

“I want to grow the game,” he told the New York Post.

Goodell said that London would get a Super Bowl only if it had an NFL franchise.