(RNN) – Willie Nelson is back in Texas recuperating after cancelling all his concerts this week.

The 84-year-old country music legend had barely started his opening song over the weekend before abruptly ending his performance, the San Diego Union-Tribune reported.

Several people at the concert told the paper that Nelson was coughing and seemed to be experiencing some difficulty breathing as he left the stage during “Whiskey River” at Harrah’s Resort Southern California in Valley Center, CA.

All his concerts for this week have been canceled, a representative said.

Nelson’s son Lukas confirmed the news on social media.

“Apologies all, Dad has the flu so we cancelled this week’s gigs in Cali and Vegas,” he said on Twitter. “If you have tickets, please contact the venue for a refund and we hope to see you on the road again soon.”

Willie Nelson doesn’t have any more scheduled concerts until February. He has eight shows on the calendar throughout the month.

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