At the final night of the Allman Brothers Band‘s “March Madness” NYC residency on March 24, band leader Gregg Allman was forced to miss the performance due to back pain caused by a bulging disc, having left the band’s March 23rd show early from a flare-up. Now Allman must delay the publicity tour for his memoir My Cross To Bear, out Tuesday (May 1), due to diagnostic cardiac testing stemming from his hernia operation. Allman was scheduled to appear on The Colbert Report and Piers Morgan Tonight.

According to a statement from his rep, Allman will undergo the cardiac tests Friday (April 27) at the Mayo Clinic in Jacksonville, FL. – the facility where he previously received a liver transplant in June 2010. These tests will determine the next steps, if any, in his medical treatment.

“I’ve been working on the book for years and am grateful for all the support I’ve received in putting it together,” Allman said in the release. “As soon as doctors give me the thumbs up to go back on the road, I will be heading out onto my book tour and I can’t wait to meet all of my fans.”

Assuming there are no complications, Allman’s publicity tour should be delayed by just a week, kicking off on May 8, just one week after the release of My Cross To Bear by HarperCollins.

The singer’s appearance on the Allman Brothers Band’s summer tour dates, which will be announced May 1, are expected to be effected by his health complications.

–Jillian Mapes, CBS Local