Metallica have said they "didn't see it coming" in regard to frontman James Hetfield's 2019 return to rehab for addiction treatment.

It was equally unexpected for metal fans when the iconic outfit postponed tour dates that fall so the singer and guitarist could seek help. At the time, the band remarked that Hetfield had been "struggling with addiction on and off for many years," only to "enter a treatment program to work on his recovery again."

Now, the group have looked back on that period with Metal Hammer. In an interview excerpt shared this week, Metallica's Robert Trujillo, Kirk Hammett and Lars Ulrich discussed their bandmate's recovery.

"We really didn't see it coming," Truijullo remembered. "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. … Meanwhile, your family's not with you and all these things are going on."

As shown in 2004's Metallica: Some Kind of Monster documentary, Hetfield entered a rehabilitation facility in 2001. But that didn't make last year's relapse any less of a bombshell for his fellow rockers.

"Whenever something happens to a band member like this, it's so deeply unsettling," Hammett explained. "It comes as a shock. You have to do a bit of scrambling just to cover some ground."

Added Ulrich, "I'm an only child, so these guys have been in my life longer than anybody else other than my parents. We know what the MO is. As you see your brothers, your friends, your partners go through ups and downs for decades, you know what the process becomes."

A month after Hetfield re-entered rehab, the Metallica drummer offered an update that Hetfield was "healing himself." In January, the frontman came roaring back with his first post-rehab appearance at a car show.

Thankfully, Metallica now appear to be back and better than ever, as evidenced in a musical appearance on The Howard Stern Show last week. Their first full show of 2020 is set for later this month.

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