OZZY OSBOURNE drummer Tommy Clufetos has commented on the cancelation of tonight's (Thursday, September 16) concert at Oberhausen, Germany's König-Pilsener-Arena after Ozzy was diagnosed with a pulled muscle in the back. As previously reported, Ozzy's doctors have prescribed a period of rest lasting 3-4 days in order for him to undergo ultrasound treatment.Clufetos tells MusicRadar.com: "I haven't spoken to him [Ozzy] yet, but I know he's had some back trouble and I think the doctors have advised him to take a break. He's had back trouble for the last two or three weeks where he's in agonizing pain. I see it because when he turns around to me I see he's in pain but the second he turns back out to the audience he's Mr. Showman. "He really cares about the audience. The only reason the show would be canceled is that he can physically not make it. He's a trooper." Ozzy Osbourne will return to North America for a month-long arena tour launching November 12 in Victoria, B.C. and concluding December 12 in Minneapolis. These shows — in support of his album "Scream" (Epic Records) and latest single, "Life Won't Wait" — are part the of the rock legend's in-progress 18-month world tour on which he's earning some of the best live reviews of his career (including raves for new guitarist, Gus G.). HALFORD, featuring legendary JUDAS PRIEST frontman Rob Halford, will perform on all dates. The first leg of arena dates will mark Ozzy's first headlining North American tour since 2007's trek for his "Black Rain" album. Tickets for the Live Nation-produced tour go on sale beginning Friday, September 17. Ozzy is now on a run of acclaimed festival appearances and headlining overseas performances, including two Ozzfest dates: London at O2 Arena September 18 and Tel Aviv, Israel at Heyarkon Park September 28. This overseas trek includes stops in Russia, Italy, Czech Republic, France, Denmark, Sweden, Greece, Finland, Norway, Germany, Romania and Turkey, before wrapping October 4 in Hungary. Ozzy then heads to Japan (October 13, 16 and 17) before returning to the U.S. to headline the Voodoo Experience festival Halloween weekend in New Orleans, Louisiana.