Keith Urban has been diagnosed with a slipped disc, but his performance schedule has not been affected, his publicist said Tuesday (Aug. 26). Urban alluded to the problem Saturday night (Aug. 23) during a concert at the Konocti Harbor Resort & Spa in Kelseyville, Calif. Contacted by CMT.com, publicist Paul Freundlich confirmed the slipped disc but declined to elaborate on the cause and severity of the injury. Urban is scheduled to travel to Canada to headline Saturday's (Aug. 30) Country Rocks Festival in Halifax, Nova Scotia. Freundlich said, "Next stop New York City for his performance at Fashion Rocks and the NFL's Kickoff Show to take place in Columbus Circle in front of an estimated 70,000." The NFL event on Sept. 4 also features R&B star Usher. Urban tapes the Fashion Rocks concert on Sept. 5 with Beyoncé, Black Eyed Peas, Chris Brown, Duffy, Justin Timberlake, Kid Rock and others at Radio City Music Hall for a CBS special to air Sept. 9.