Carrie UnderwoodThink Peyton Manning and Drew Brees are nervous this weekend? Well, throw Carrie Underwood into that mix, as well. The country superstar will sing the national anthem at the Super Bowl, and she says she's already full of jitters.

"My biggest fear is words," Carrie tells ABC News. "Of course you sing these songs a million times, and everybody knows the words. But if you're gonna mess up, that would be the one time to do it."

So what team will she be rooting for once she's able to settle and enjoy the game -- New Orleans Saints or the Indianapolis Colts?

"I love [Saints Coach] Sean Payton," Carrie confesses, remarking that the Saints have 51% of her support. "He came to a concert, so that's where that extra one percent [comes from]!"