Aerosmith canceled their show in Concord, California Wednesday night — with reports circulating that the cause was drummer Joey Kramer having a heart issue.

The band’s site says the cancellation is due to illness. TMZ reports that Kramer had heart issues on Tuesday and that “a source close to the band tells us Kramer has had heart issues in the past.” TMZ also reports that members of the crew have been told the show Saturday in Quincy, Washington will also be cancelled. There’s been no word from the band’s camp as of yet beyond Wednesday’s show being canceled due to illness.

After the Concord show was canceled, opening act Slash featuring Myles Kennedy and The Conspirator quickly booked their own show for Wednesday night at The Fillmore in nearby San Francisco.