Simon Pegg wanted an older actor instead of Seth Rogen to voice the role of alien Paul in his new sci-fi comedy film.
The British actor - who stars opposite an extra-terrestrial voiced by Seth in the comedy road-trip film - originally wanted an older star for the role but was convinced by a studio someone younger might work better.
He said: "We had older actors in mind - somebody like Rip Torn.
"But when we were talking to the studio casting people, they were keen on people who were relevant to the comedy audience.
"When they said Seth, I realised that he was young, but he had an old voice. So it was a no-brainer. When I see the movie, I forget that Seth is even in it."
He told HollywoodandFine.com: "The name had to be ordinary, though we also thought about coming up with a name that was more doglike".