Diesel, who passed on the lead role in "Daredevil" before Affleck took it on, insists he doesn't care who plays the Caped Crusader, but the Oscar winner will be more than able to handle the role.
He tells the Huffington Post, "Let him live is my motto, let him live. Let Warner Bros. hire whoever they want, let Ben do whatever he wants. He got an Oscar, give him some credit. Leave him alone."
Fans of Batman who are unhappy with Affleck's casting have launched an online petition in the hope of changing movie executives' minds.
Affleck will suit up alongside Henry Cavill in the sequel.