The Boss is back, as 74-year-old Bruce Springsteen returned to the concert stage this week in Phoenix after postponing his world tour last September.

But in an interview with SiriusXM’s E Street Radio host Jim Rotolo, Springsteen said the peptic ulcer disease that sidelined him had him concerned he might not be able to sing again.

“Once I started singing, you know, you can rehearse singing, but your voice isn’t the same in rehearsal. You don’t have that edge of adrenaline that really pushes it into a better place and the thing when I had the stomach problem, one of the big problems was I couldn’t sing,” Springsteen said.

“You sing with your diaphragm. My diaphragm was hurting so badly that when I went to make the effort to sing, it was killing me, you know? So, I literally couldn’t sing at all, you know, and that lasted for two or three months, along with just a myriad of other painful problems.”

Things got so bad, Springsteen admitted that he feared that he might never regain his ability to sing.

“I was, during the course of it, before people told me, ‘Oh no. It’s gonna go away, and you’re gonna be OK,’ you know, you’re thinking like, ‘Hey, am I gonna sing again?’ and you know, this is one of the things I love to do the best, the most, and right now I can’t do it.,” Springsteen said.

He continued, “You know, I can’t do it, and it took a while for the doctors to say, ‘Oh no. You’re gonna be OK.’ At first, nobody was quite saying that, which made me nervous, you know, and at the end of the day, I found some great doctors, and they straightened me out, and I can’t do anything but thank them all.”

The current tour will conclude on November 22 in Vancouver, Canada, visiting 17 countries across 52 dates, including a September 15 when Springsteen headline date at the Sea.Hear.Now Festival in Asbury Park, New Jersey.