Emily Blunt was Jon Favreau 's first choice to play Natasha Romanoff in Iron Man 2 .
She starred in the Toby Spanton-directed short film Curiosity , and was director Jon Favreau 's first choice to play Natasha Romanoff / Black Widow in Iron Man 2 , but due to scheduling conflicts with her role in the comedy Gulliver 's Travels , she was forced to yield the role to Scarlett Johansson .
Emily Blunt