An undisclosed illness forced Willie Nelson to postpone two recent concerts, one scheduled for Sunday night (Nov. 13) at the Wagner Noel Performing Arts Center in Midland, Texas, and another on Tuesday (Nov. 15) at Lubbock, Texas' City Bank Auditorium.

News West 9 in Midland reports that a press release sent out by the Wagner Noel PAC explained that Nelson was "feeling under the weather." A report from, meanwhile, says only that a representative of Select-a-Seat shared the news of Tuesday night's cancellation; no further details were announced. Those with tickets to Nelson's Midland concert have been asked to hold onto them until the show can be rescheduled; information about a new date for the Lubbock show is not available.

Nelson, now 83, still tours regularly; in fact, he played Billy Bob's Texas' 35th anniversary celebration on Saturday night (Nov. 12). His tour calendar has a number of dates on it throughout the rest of 2016 and into 2017, including a performance at the 2017 Stagecoach Country Music Festival, set to take place in April. Nelson's next scheduled show is on Wednesday (Nov. 16) at the Stafford Centre in Stafford, Texas.

Back in late 2015, Nelson and Merle Haggard were forced to postpone the first few dates of their 2015 Django and Jimmie Tour due to a medical concern on Nelson’s end. The country icon later revealed that he had a stem cell operation to help his lungs.

“Over the years, I’ve smoked a lot of cigarettes, and I’ve had emphysema and pneumonia four or five times, so my lungs were really screwed up," Nelson said at the time, "and I had heard that this stem cell operation would be good for them. So I said, ‘Well, I’m gonna try it out.'"

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