While on Larry King Now, Green revealed that he believes Affleck isn't scary enough to be the Batman needed in a Batman/Superman film. He tells the talk show host, "You’ve got to remember that at the core of that character, Batman’s a crazy person. Batman has no powers. Batman is a rich, screwed-up kid whose parents were killed in front of him, who with his money and insanity decided to become a vigilante symbol to combat darkness. Christian Bale was great because he plays that part."
Green also explains Affleck may not look old enough to be a veteran Batman, saying, "If this movie is meant to be the idealistic alien, humans-before-all-else Superman, and this is supposed to be the grizzled, weathered Batman who’s been living in Gotham fighting crime himself for 10 years, you need a guy who’s older.
"… you need a guy that a Henry Cavill Superman is gonna be actually scared of."
While saying Affleck is a good actor, Green says, "There is only so much you can act a role before people are or are not going to believe you in that role. I'm not going to play an MMA fighter."