Carrie Underwood Nervous About Super Bowl Performance

 Rick Diamond/WireImage.com

Carrie Underwood is nervous she'll make a performance fumble at this Sunday's Super Bowl.

Said the singer, 26, who will sing the National Anthem, "My biggest fear is the words.

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"Of course you know the words," she continued to USA Today. "But if you're going to mess up, that'd be the time, right?"

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Underwood — who says she'll be rooting for the Saints — also joked about her fave new song: "Pants on the Ground," as performed by General Larry Platt on American Idol two weeks ago.

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"As a songwriter I know we all aspire to write something that is catchy and has a message," she said. "And I think the youth of America can learn a lot from Pants on the Ground. And they can pull their pants up… because it causes all kinds of back problems. I've seen the studies."

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