The person spoke to the AP on condition of anonymity Wednesday, because the musicians' performances were not going to be announced before the game.
Usher and Slash are supposed to join the Black Eyed Peas, who are the main halftime act for Sunday's NFL championship game between the Pittsburgh Steelers and Green Bay Packers at Cowboys Stadium.
The NFL said in November that the Black Eyed Peas would be the featured Super Bowl halftime performer. Past halftime acts have included U2, the Rolling Stones, Bruce Springsteen & The E Street Band, Paul McCartney and Prince.
