Joss Whedon was concerned 'Avengers Assemble' might turn into a ''sausagefest''.
The 47-year-old director cast Scarlett Johansson in the superhero movie - which sees her reprise her role of Natasha Romanoff / Black Widow from 'Iron Man 2' - to avoid the film being dominated by its male stars Robert Downey Jr., Chris Evans, Chris Hemsworth and Mark Ruffalo.
Scarlett explained to Empire magazine: ''Joss said to me, 'I want to do everything I can to keep this from being,' in his words, 'a sausagefest.' I said, 'That's disgusting, but okay.'''
Scarlett was also keen to ensure her alter-ego - who can be seen battling villains in a skin-tight catsuit in the movie - was not portrayed as a ''love interest''.
She added: ''I knew that I didn't want to play a love interest. That's not who Widow is. I think Joss understood the importance of having a female perspective. He's a very sensitive guy. He works really well with women. He obviously can write for them!
''He loves strong and independent women and he's got a certain understanding of and an appreciation for, women who take charge of the situation, of themselves so it was clear to me that the character would not be underwritten.''