Mumford and Sons 2013, Bassist Hospitalized UPDATE: Jack Johnson to Replace Band at Bonnaroo

In a last minute decision, folk rockers Mumford and Sons have opted to pull out of their Saturday performance at the Bonnaroo Music Festival in Manchester, TN. Bassist Ted Dwane is recovering from brain surgery earlier this week. 

On Tuesday the group announced via its website that Dwane had been feeling unwell, and a visit to a doctor's office led to the discovery of a blood clot on the musician's brain. The group immediately postponed its shows in Dallas, Woodlands, TX and New Orleans, but left the possibility of playing at Bonnaroo open. 

Not all is lost however. A fellow fan of the acoustic guitar, Jack Johnson, will step in to fill Mumford's place on Saturday. The artist was already making an appearance with the band Animal Liberation Orchestra at the festival, but Johnson said that the band he tours with as a solo artist was ready to make it work. 

"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."

Bonnaroo isn't the only festival that Mumford has had to drop due to Dwane's health issues. According to the band's website, they'll also be missing out on the Telluride Bluegrass Festival in Colorado and a headlining show in Bonner Springs, KS. The group will hopefully take the stage again for the Glastonbury Music Festival in England and make the trip back to the U.S. for Lollapalooza in August. 

The group indicated that Dwane is recovering well from the emergency surgery, and their potshots at the bassist indicate he's in good spirits. 

"Now it has been medically proved that he does indeed have a brain," they wrote.