When a superstar band is forced to cancel a festival appearance, they can only be replaced with another major act. That's exactly what Metallica is doing, filling in for Green Day as headliners at the Voodoo Music + Art Experience in New Orleans on Saturday, October 27.

"Our good friends and fellow Bay Area residents Green Day had to unfortunately cancel their plans to be there, so we are more than happy to fill in for them in our own unique way," said drummer Lars Ulrich. "We're hoping we can fill those very large shoes and do them proud."

Green Day had to drop out because singer-guitarist Billie Joe Armstrong's is currently in rehab for substance abuse. His stint follows an onstage meltdown at the IHeartRadio Festival in Las Vegas last month. The timing couldn't be worse, considering the band released its new album, ‘¡Uno!’ a few days later.

"Canceling shows is something we rarely do," Green Day drummer Tré Cool said. "We never want to let our fans down, and we are grateful for all of you being understanding during this time." Green Day are hoping to begin their fall tour in Seattle on the expected date of Nov. 26.

Neil Young and Crazy Horse will headline the first night of the Voodoo Music + Art Experience (Oct. 26), with Jack White closing the three-day event on Oct. 28.