Watch: MÖTLEY CRÜE Joined By DEF LEPPARD's RICK ALLEN For 'Primal Scream' Performance At Florida Concert

DEF LEPPARD's Rick Allen joined MÖTLEY CRÜE on stage last night (Sunday, March 12) to perform the song "Primal Scream" during CRÜE's set at Hard Rock Live in Hollywood, Florida.

Allen shared the drumming duties for the song with MÖTLEY CRÜE's Tommy Lee, with the two musicians positioning their drum risers side by side for the performance, which was part of the two bands' "The World Tour".

During an appearance on a recent episode of the "Appetite For Distortion" podcast, Allen was asked to weigh in on MÖTLEY CRÜE guitarist Mick Mars's recent decision to no longer tour with the legendary rock act because of his long struggles with degenerative disease ankylosing spondylitis. Ankylosing spondylitis is a type of arthritis that causes inflammation in the spine joints and ligaments and can lead to stiffness over time, according to the National Institute Of Arthritis And Musculoskeletal And Skin Diseases.

Allen, who previously toured with Mars as part of DEF LEPPARD and MÖTLEY CRÜE's 2022 "The Stadium Tour", said: "It was Mick's decision to really move on and just get to the next part of his life. And we all know that Mick has suffered terribly, terribly with pain; you see it on his face all the time. And I think the only time I ever saw him truly in his element [was] when he was up on stage playing with the band. It was more his decision. That must have been a super hard decision. I mean, it would have been different if the guy was being thrown out of the band, but it wasn't like that at all. It was a personal choice that he made. And you can't say that that's wrong. It was right for him at the time.

"Over the months — well, actually years — that I've known him, I really started to talk to him," Rick continued. "So unassuming. Such a soft, gentle soul. And when I first met him years ago, I was actually quite afraid, you know. [Laughs] But he's the exact opposite of that — just a really sweet, generous person. So it must have been a very difficult decision for everybody to have to go through that."

The 71-year-old Mars — whose real name is Robert Alan Deal — served as MÖTLEY CRÜE's lead guitarist since the band's inception in 1981.

A day after Mick announced his retirement from touring last October, the remaining members — bassist Nikki Sixx, singer Vince Neil and drummer Tommy Lee — vowed to "continue the legacy." In a statement, they said: "While change is never easy, we accept Mick's decision to retire from the band due to the challenges with his health. We have watched Mick manage his Ankylosing Spondylitis for decades and he has always managed it with utmost courage and grace. To say 'enough is enough' is the ultimate act of courage. Mick's sound helped define MÖTLEY CRÜE from the minute he plugged in his guitar at our very first rehearsal together. The rest, as they say, is history. We'll continue to honor his musical legacy."

The statement continued: "We will carry out Mick's wish and continue to tour the world as planned in 2023. No doubt will it take an absolutely outstanding musician to fill Mick's shoes so we are grateful that our good friend, John 5 has agreed to come on board and join us moving forward. We'll see all you Crueheads out on the road!"

John 5 said: "I'm honored to carry on Mick's legacy and am looking forward to playing these songs."

In his statement, Mick said that he had decided to step back from live shows due to his "ongoing painful struggle" with ankylosing spondylitis and while he will continue to be a member of the band, he cannot "handle the rigors" of touring life.

The statement read: "Mick Mars, co-founder and lead guitarist of the heavy metal band MÖTLEY CRÜE for the past 41 years, has announced today that due to his ongoing painful struggle with Ankylosing Spondylitis, he will no longer be able to tour with the band. Mick will continue as a member of the band, but can no longer handle the rigors of the road. A.S. is an extremely painful and crippling degenerative disease, which affects the spine."