Metallica may be too busy on tour right now to think too much about their next album, but they know that they will most likely work again with Rick Rubin when they are ready to record the follow-up to 2008's 'Death Magnetic.' No, 'Lulu' doesn't count.

“The main thing for us was getting to the core and essence of Metallica, and that’s the reason we chose to work with him," said James Hetfield. "He gets the best out of artists who have been around for a while, I believe. That’s what we wanted him for.”

“Rick is not a one-trick pony,” said Lars Ulrich, who briefly met with Rubin in Los Angeles to discuss working together again once Metallica's schedule is free. “He builds a particular ease around whatever your task is. Whatever we want to do with the next record, he’ll help us with that.”

Both Rubin and Metallica are currently occupied. Rubin is behind the board for the Black Sabbath reunion album, and Metallica are touring Europe, where they are performing the 'Black Album' in its entirety -- backwards.