(CBS/AP) Rocker Gregg Allman is postponing his upcoming book tour for heart tests.
He's scheduled to undergo tests Friday at The Mayo Clinic in Jacksonville, Fla., the same facility where he underwent a liver transplant in June 2010.
The Rock and Roll Hall of Fame member recently had hernia surgery related to the transplant and says he feels as well as he has in some time. He said in a Thursday afternoon phone interview that he's experiencing arrhythmia, a problem with the rate or rhythm of the heartbeat.
"There's a little reggae in there somewhere," he said.
It's unclear whether Allman's heart problems are related to the transplant.
The founding member of The Allman Brothers Band will start his book tour to promote his memoir "My Cross to Bear" on May 8 if doctors find no serious problems.
A website post explains: "We wanted to let everyone know that Gregg is excited for the book launch and is still planning to get out on the road starting May 8th. We'll be posting updates regularly. Let's all send positive vibes Gregg's way!"
In 1999, Allman found out he had chronic Hepatitis C. He's now a spokesperson for Tune Into Hep C, a national awareness campaign thatand Natalie Cole.
"I went to the doctor because I just didn't have any energy," Allman explains on the organization's website. "Like many people with chronic hepatitis C, I lived for decades without knowing I had the disease."