Actress Rooney Mara comes from a mixed football family – Pittsburgh Steelers on mom Kathleen’s side, New York Giants on dad Chris’ side – but her families’ dealings with the media offered little preparation for the media blitz she’s experiencing for her role in “The Girl With the Dragon Tattoo.”

“It’s such a different world, I don’t think anything they could have said would ever prepare someone,” Mara said during a quick phone call from New York. “It’s such a different animal – the sports world is all about sports, and in this world, it’s not all about acting or movies.”

It’s about appearing on “Late Show With David Letterman” or “Today” and jetting to back-to-back premieres and posing on red carpets alongside co-star Daniel Craig.

“I never thought of him as James Bond,” Mara said. “I wasn’t very familiar with those films, and Daniel’s such an incredible actor, he kind of instantly was (Mikael) Blomkvist,” the Swedish journalist character. “I can’t imagine anyone else having played the part, I thought he was so perfect for it.”

Mara said her parents had read the “Dragon” books and were prepared for the movie’s R-rated content, which includes partial nudity, sexual degradation and rape.

“They were all very aware of what was going to be in the film, and they’ve all actually already seen it and they really loved it and were really supportive,” she said.

To immerse herself in Lisbeth Salander’s world, Mara moved to Sweden, where she found the architecture and people stunningly beautiful. Lisbeth began to feel “very familiar” to her.

“It’s hard to articulate. It’s just a feeling that I had while reading the books. I felt like I knew her and I really understood her,” she said.

The actress looks unlike her character, whose chopped hair is dyed black. Lisbeth’s eyebrows are bleached, and she sports multiple piercings. Before filming each day, Mara had temporary tattoos inked onto her skin.

Although much has been made of Mara’s physical transformation, she wasn’t fazed by it.

“I was already deeply engrossed in the character. I had spent two and a half months auditioning and I felt really ready to do it. I was just really excited about it.”

The role has earned her a Golden Globe nomination for best actress alongside Meryl Streep, Glenn Close, Viola Davis and Tilda Swinton.

Mara, who famously dumped Mark Zuckerberg in director David Fincher’s “The Social Network” and also starred in a remake of “A Nightmare on Elm Street,” had a hard time shaking Lisbeth after she doffed her leather jacket, profane T-shirts and combat boots.

“It was definitely a hard character to shake off, especially because physically, I still kind of looked like her,” she said.