Ward previously said that he sat out because of a contract dispute.
"I was offered a contract, and I couldn't sign it," Ward said. "I would never, ever show up for a commitment that I could not do physically. ... It was one of the toughest decisions that I ever had to make, because I absolutely and without question wanted to play."
Speaking to the New York Daily News, Osbourne stated that the real reason for Ward's absence was his physical condition.
"I don't think he could have done the gig, to be honest," Osbourne said. "He's incredibly overweight. A drummer has to be in shape. He's already had two heart attacks. I don't want to be responsible for his life."
Osbourne said "the door is always open" for Ward to return.
Rage Against the Machine drummer Brad Wilk played on the most-recent Black Sabbath album 13, and Tommy Clufetos is the touring drummer.
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