He shocked fans by making a surprise departure in 2010 after attempting to persuade his bandmates to take a break from the rigours of recording and touring.

By the time he'd reconsidered and asked to return, they'd hired new sticksman Mike Mangini, and they're poised to release their second album with him.

Portnoy says: "I would do it in a heartbeat. They are the ones who have closed the door on it.