Jack Johnson is replacing Mumford & Sons as the Saturday night headliner at Bonnaroo.
Ted Dwane, bass player for Mumford & Sons, is ungergoing treatment for a blood clot in the brain, forcing the band's cancellation. He has been discharged from the hospital and is recovering from the procedure but is not yet ready to play.
Festival officials announced the move this morning. Johnson last headlined at Bonnaroo in 2008.
"I called my band and asked if they were up for it," Johnson said in a statement. "Long story short - they are headed this way. I've got a lot of lyrics and chords to relearn by Saturday night. I was here to play the first Bonnaroo, and it is a very special festival to my band. We are excited to hit the stage again. Get well Ted!"