The first of Willie Nelson's upcoming shows with Merle Haggard on the Django and Jimmie Tour have been called off, as the "On the Road Again" singer has an unknown medical issue.

"I have no additional details but it is only the first three dates," a rep for Nelson says. "The rest of the tour is on schedule."

Further information comes from the Florence Civic Center in Florence, S.C., where the duo were scheduled to kick off the tour on Thursday (Oct. 15). That show has since been been rescheduled for April 6, 2016.

“This is all news to us at the moment and we’re still getting details on Willie’s medical concern. We’ve been told this is not life-threatening, but will require several weeks to fully recover," Nick Hooker, Senior Marketing Manager for the venue, says. "We will keep you updated as more information comes to light."

"We know this is last-minute and we sincerely apologize for any inconvenience, but our hearts and best wishes go to Willie Nelson and his family during this time of health concern," Hooker adds. "Get well soon Willie, we can't wait to see you in April alongside Merle Haggard."

Fans planning to attend the Django and Jimmie Tour kickoff show can keep their tickets for the April date.

The 82-year-old Nelson has been very dependable and remained mostly healthy over the last decade, despite a very intense touring schedule. He canceled shows in 2012 after being hospitalized with breathing troubles. The most notable story pertaining to his physical well-being came in 2014 when he shared he'd received a 5th degree black belt in Korean Martial Arts.

Shows in Roanke, Va., at the Berglund Center Coliseum (Oct. 16) and Reading, Penn., at Santander Arena (Oct. 17) have also been affected. The Oct. 21 show in Bloomington, Ind., is assumed to be happening as scheduled.

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