James Hetfield says that Kirk Hammett "wasn't involved" in the songwriting process for METALLICA's new album because his "riffs weren't there."

Hammett has penned plenty of great instrumental parts over the years for METALLICA alongside the songwriting team of Hetfield and drummer Lars Ulrich, but that's not the case for "Hardwired… To Self-Destruct".

Hetfield told France's Metal XS: "Kirk was not part of the writing. Kirk obviously came in and did the solos. But Lars and I… You know, Lars and I always have done this, but with contributions from other people on their riffs and things. Kirk's riffs weren't there. I know he talks about him losing his phone and things like that with the riffs, but… No, he wasn't involved in the process. And Robert [Trujillo, bass] was there. The intro to 'ManUNkind' is Robert; that is him, and it's beautiful. But it is Lars and I doing what we always do — put the songs together."

Hetfield also talked in more detail about the "Hardwired… To Self-Destruct" songwriting process, explaining: "[The songs] were all put together over the course of time — I would say maybe a year and a half. But the riffs… I mean, the riffs could have been around for a little longer. But there's no… I mean, it's all new. There's nothing that was left over from other albums or anything, so it's all new. Some are riffs that were on my riff collection, and some were, 'Let's just go out and play,' and some just came about there. So some are super fresh, and some are, obviously, from the last year."

In a recent interview with Metal Hammer magazine, Trujillo said that Ulrich felt it was "really important" to connect with Hetfield on the follow-up to 2008's "Death Magnetic" by involving him more in the creative process.

Trujillo said: "Lars focused more on simplifying the creative journey, and locking into James and really bringing him in for this album. It's Lars's vision, and I'm happy to support whatever we need to do."

Hammett recalled the "devastating" time in 2014 he lost his phone containing hundreds of song ideas for the tenth studio album, which meant he "had to start at zero" again. "By the time I got a few ideas flowing and formed, most of the songs were already written," he said, calling the experience a "very bitter pill to swallow."

He forced himself to look on the bright side. He said: "I had to think, 'Okay, I have stuff — but it looks like it's going to make it on to the next album."

Hammett added: "For me, being in this band, I always want to contribute. I always have a lot of musical concepts and ideas to bring to the table. Obviously, that was not meant to be this time, and I had to accept that fact. So I focused on my solos, just making sure that my playing on the album was at its best — at its full potential. Hopefully I can bring my ideas to the next METALLICA album. I just hope it's not another eight years."

METALLICA will be the featured musical guest on this Wednesday's (December 14) edition of ABC's "Jimmy Kimmel Live!" As with most of Kimmel's musical guests, the band will perform a mini-concert on the show's outdoor stage on Hollywood Boulevard, with the street likely to be closed for several blocks in either direction to accommodate thousands of fans. A portion of the performance will be aired on that night's show, which starts at 11:35 p.m.

As previously reported, METALLICA will also play a special intimate show this Thursday (December 15) at the Fonda Theater in Hollywood, California. All proceeds from the sale of tickets to this show will be donated to Los Angeles Regional Food Bank. Fans are also encouraged to bring canned foods and non-perishable items to the show for donation as well.

"Hardwired...To Self-Destruct" debuted at No. 1 on The Billboard 200 album chart last month. An extensive world tour is in the works for 2017.