"This whole song leading into it, it's like, it's time! It's time for football!" said Underwood.
NBC's been showcasing some of the tongue in cheek auditions to sing "Waiting all day for Sunday night."
But it's a six time Grammy winner who's carrying on the tradition.
"I'm a football girl! I love football!" Underwood said.
Stars from 13 NFL teams came together to film the music video that goes along with Underwood's rendition.
"Sunday night's huge. You're the only game on TV! Everybody's watchin' and that's what you worked for," said Houston Texan defensive end JJ Watt.
And come this Sunday Underwood will usher in the battle between the Giants and Cowboys that launches prime-time TV's number one show.
"It's ingrained in the American soul! It's what we do, we get together and we watch football!" said Underwood.
And a gridiron anthem gets an all new sound.
Not only will Underwood be part of "Sunday Night Football" this season, but come the holidays, she'll also be starring, along with "True Blood's Steven Moyer, in NBC's live stage production of "The Sound of Music."