Recurring vocal troubles have forced Thompson Square to cancel four shows scheduled for this weekend. Keifer Thompson admitted to being plagued by a "very serious vocal condition" for several weeks, saying he is finally listening to his doctor's orders to stop performing.

"I was urged by doctors to cancel Thompson Square's appearances and go on complete vocal rest several weeks ago; however, neither Shawna nor I wanted to disappoint our fans, which we love and respect dearly," the singer writes at the duo's website. Simply resting his vocals offstage was not enough to ease what's bothering him.

"Words cannot express how devastated we both are to bring this news to our fans," he adds. "We hope that you will understand what a difficult decision this has been and know that we can't wait to get back out on the road and make it up to you as soon as possible."

Five performances scheduled from May 29 to June 2 have been canceled. Four of the dates were opening slots on Luke Bryan's Dirt Road Diaries Tour. Cole Swindell is stepping in to replace Thompson Square on the Bryan tour dates, and those shows will go on as scheduled.