Appearing on "The Colbert Report" Tuesday to promote his new film, "Oz the Great and Powerful," Franco mentioned his plans for the project, adding: "There's a character, Slim. We haven't cast him yet ... You could do it."
"Is it a big time commitment? Because I've got this show to do," Colbert responded, laughing.
Franco later told Colbert he will play George in the stage adaptation of John Steinbeck's classic novel - and again tried to coax the talk show host to join him.
"If you want to play Lenny ..., " he added.
No official word on when (or if) this production will really happen, and Franco's representatives did not immediately respond to TheWrap's requests for comment.