"Despite doctor's orders, she performed on a bruised vocal cord in (New York City) on August 14," Minaj's rep told E! News of the unfortunate circumstances. "As a result, the cord has gotten worse."
Minaj was originally set to take the stage at the two-day music festival, which takes place in Hylands Park and Weston Park in Essex, England, but recent X-rays have shown that she'll have to "rest her voice for a few days" to save her voice, the Associated Press reports.
Last Tuesday, the singer, 29, gave a performance to remember at the Roseland Ballroom, where she brought out Lil Wayne, Drake and Foxy Brown to help her make her first official headlining show in the Big Apple.