Metallica has opened up about frontman James Hetfield re-entering an alcohol addiction treatment program last September. Robert Trujillo told UK's Metal Hammer Magazine, “We really didn't see it coming. James seemed like he was fine, but then you look back and you try to analyze the situation over time and see where there were red flags.”

He continued, “Being on the road can be very challenging, and I would imagine for James, to get up there in front of all those people and have to be 'on,' meanwhile your family’s not with you and all these things are going on, it builds up.”

Kirk Hammett added, “Whenever something happens to a bandmember like this, it's so deeply unsettling. It comes as a shock. You have to do a bit of scrambling just to cover some ground.”

In other Metallica news, the band shared a version of “For Whom the Bell Tolls” yesterday (August 20th) from their upcoming S&M2 (Symphony and Metallica²) concert film, which is due out on August 28th.