Robert Downey Jr. is seeing his career take off thanks to Iron Man. And, according to the Chicago Sun Times, though, his next film project might be centered around an iron man of a different kind.

Rumors are circulating that the actor may sign on to play Hugh Hefner the Playboy founder's big-screen biopic.

It's not a done deal yet, but sources say Hefner has approved of Downey to play him in the movie, which has the apt working title of Playboy.

There's no word on when the cameras might actually begin rolling on the movie, but it could happen as soon as next summer, depending on Downey's Iron Man 2 filming and the finalization of the Hefner script.