NEW YORK (AP) — The Willie Nelson & Family and Alison Krauss concert date scheduled for Saturday at Big Sandy Superstore Arena has been cancelled. Nelson cited a “breathing problem.”

The Big Sandy Superstore Arena says tickets purchased will be refunded at the point of purchase. Ticketmaster refunds should be received within 7-10 business day.

The 86-year-old singer apologized on Twitter late Wednesday, writing “I need to have my doctor check out.”

He wrote “I’ll be back.”

Nelson was due to perform at the Farm Aid concert with John Mellencamp, Dave Matthews, Neil Young and Bonnie Raitt on Sept. 21. His tour was scheduled to end on Nov. 29 in Thackerville, Oklahoma.