Willie Nelson had to cancel concert appearances this past weekend due to illness.

The 91-year-old was due to kick off the Outlaw Music Festival Tour on Friday, June 21, but hours before showtime announced on social media that he could not perform on "doctor’s orders."

"We regret to inform you that Willie Nelson is not feeling well and, per doctor’s orders, has been advised to rest for the next four days," a statement posted to his official X account stated.

It continued, "he is expected to make a quick recovery and join the Outlaw Music Festival tour next week."

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They announced that Lukas Nelson and the Family Band, led by Willie’s son, would perform "a special set to include Willie’s classics and other songs."

The other acts on the line up, Bob Dylan, Robert Plant and Alison Kraus, and Celisse, performed as planned.

Nelson’s representative released a statement, stating, "Willie will be fine. I live in Los Angeles and will fly next week to see the performances on the east coast. I can’t wait."

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Though a specific return date was not given, the next show after Nelson’s break is scheduled for June 26 in Virginia Beach, Virginia.

The 2024 Outlaw Music Festival was announced in February on social media.

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On the tour’s website, Nelson wrote, "This year’s Outlaw Music Festival Tour promises to be the biggest and best yet with this lineup of legendary artists. I am thrilled to get back on the road again with my family and friends playing the music we love for the fans we love."

Last year around his 90th birthday in April, Nelson told AARP he was happy to celebrate the milestone by being on tour, saying, "Working is really good for me, no matter what kind of show it is."

When asked if he's ever considered retiring from the road, Nelson said, "Jokingly, I retire after every tour."

He continued: "But I’m always ready to go back again. I like the bus. I have everything I need on the bus. I never have to go into a hotel room anywhere. It’s not that bad."