The Charlie's Angels actress will play the assistant to Jonny Lee Miller's Holmes in the forthcoming CBS adaptation, which she stated would turn Arthur Conan Doyle's detective series "on its head in a very big way".
"Whether it succeeds or fails, I feel I'm doing something different and exciting," BBC Newsbeat quotes her as saying. "For me it's about pushing forward.
"Playing a role that has been historically a male figure and also something that is obviously lore because it is very English-based... that's something I always like to do - push the envelope."
The Elementary pilot also stars Prime Suspect actor Aidan Quinn and is written by Medium's Rob Doherty.
Sue Vertue, executive producer of BBC series Sherlock, recently described the similarities between the show and Elementary as "extremely worrying".