The band canceled a concert in Sheffield, northern England, Monday after Mills fell ill with flu-like symptoms. The show was rescheduled for June 15. A concert scheduled for Tuesday in Glasgow, Scotland, also was called off.

Stipe said doctors had told Mills he should be able to perform Wednesday, February 23, when the band is due to play in Birmingham, central England.

He said the bass player’s illness began with a case of flu and evolved into an inner-ear infection.

“Mike held out until the last possible moment because he didn’t want to disappoint fans, but 45 minutes before we were due on stage I looked at him and realized there was no way he could go on,” Stipe said. “He could barely stand.

“We’re all incredibly disappointed because we’re not a band that cancels shows left and right. Last time we canceled a show for any reason was nine years ago.”

R.E.M. is set to perform in Belfast and Dublin, Ireland, over the weekend before flying to South Africa for the next leg of its tour.