The sequel to David Fincher's The Girl with the Dragon Tattoo is in development, but it was rumoured recently that Craig was demanding a pay rise and might therefore be written out.
"It would never be a possibility," Mara told MTV. "He wouldn't be written out."
Mara also revealed that she had been "talking a lot" with Fincher about the sequel, but was unsure of whether he would return to helm the movie.
"I would hope that he would, but no matter what, he'll definitely have some sort of involvement," she said.
Watch Rooney Mara discuss The Girl with the Dragon Tattoo with Digital Spy below: