And Butler believes the sticksman would never have been able to handle the pace of touring - even though activities were cut back to make allowance for guitarist Tony Iommi's cancer fight.

"We started off with Bill and it just didn't happen. To be blatantly honest, he just couldn't do it any more," Butler tells Time Out Dubai. "He was thinking that we could take, like, ten years to do the album - whereas we knew we only had so long to do it and get out on tour, while you're still good at what you do.