13 Movies Saved By Ridiculously Last Minute Changes

4. Paul Dano Replaces Kel O'Neill - There Will Be Blood

Paul Thomas Anderson's towering epic originally saw relatively unknown actor Kel O'Neill playing the part of sycophantic preacher Eli Sunday, but two weeks into shooting, Anderson replaced him for reasons that have never been made explicitly clear. The rumour, however, is that the intensity of Daniel Day-Lewis' method acting made him too anxious to work opposite the statuesque actor.

Either way, Paul Dano was originally only set to play the small part of Eli Sunday's brother Paul, but Anderson decided to offer him the role of Eli also, transforming the siblings into twin brothers.

It's a decision that was pure cinema magic, for though the film absolutely belongs to Day-Lewis' stonking, Oscar-winning performance, Dano's dual turn as the Sundays is only a few steps behind.

Simply, it's hard to imagine O'Neill delivering such a terrific performance, so all things considered, it was definitely the right decision, regardless of whatever Anderson's reasoning ultimately was.