According to the publication, the 84-year-old was taken to a local hospital after departing the stage early on in his performance at the USANA Amphitheatre.
Several hours later, the star took to Twitter to share that he had been affected by altitude sickness.
“This is Willie I am sorry to have cut the SLC show short tonight,” he penned.
“The altitude got to me I am feeling better now & headed for lower ground.”
Nelson has battled multiple health complaints in recent months, having cancelled multiple gigs earlier this year due to a “bad cold.”
At the time, an anonymous source told Radar Online that the musician was “deathly ill,” a claim his publicist quickly refuted.
This article first published on New Idea.