The Lumineers are facing a race against time to prepare for their upcoming appearance at Britain's Glastonbury festival after a bandmember fell sick just days before the big show. The folk rockers axed a performance at the Firefly Festival in Delaware over the weekend (22-23Jun13) due to "illness in the band" and told fans they needed time to recuperate. A statement from the group reads, "The health and well-being of the band along with giving the fans the best possible performance remain our top priority. Unfortunately given the circumstances, both of those things would be in jeopardy if we went ahead with our set (at Firefly)." They are next due on stage at the legendary British music event in Somerset, England on Friday (28Jun13). The show will mark the group's debut performance at the iconic festival.