The country music veteran announced on Wednesday (14Oct15) he was having to push back the first dates of his joint trek with Merle Haggard due to a mystery health problem, sparking fears for his wellbeing.

However, his musician son Lukas has since reached out to devotees online to insist there is nothing to worry about, although he did not share any further information about what actually ails the 82 year old.

Taking to Twitter.com, he writes, "Thanks for the prayers and love for dad, his health issue is minor and he's doing great, love to all..."

Nelson is still scheduled to perform at the American Roots Music & Arts Festival in Raleigh, North Carolina on Sunday (18Oct15), while he is now expected to kick off his tour with Haggard on Monday (19Oct15) with a gig in Virginia, which was originally due to take place on Friday (16Oct15).