Chris 'nervous' by Captain America

Chris Evans has admitted he has nerves over playing famed superhero Captain America.

The Fantastic Four actor said he didn't immediately say yes to the role in Captain America: The First Avenger because of its implications.

"It wasn't an easy yes, I get nervous - Captain America means a lot of this," he told MTV.com.

"[Playing] Captain America just changes things, and there's really no off switch once you walk down that road."

Despite his initial doubts, the 29-year-old, who next appears with Michael Cera in Scott Pilgrim Vs The World, still considers it an opportunity of a lifetime.

"There's nothing wrong with the project," Chris explained.

"I love the people involved, the character, the script, Hugo [Weaving]. There was nothing wrong there, it was just about the lifestyle change and whether or not I was willing to do it."

The film, scheduled for release in 2011, also stars Hugo Weaving, Samuel L Jackson, Dominic Cooper and Hayley Atwell.

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