Mike Campbell is ready to shed some light on his complicated friendship with the late Tom Petty.

As a founding member of Tom Petty and the Heartbreakers, Campbell had a front-row seat to the singer’s career as he helped the rock group cement their place in music history with such hits as “American Girl” and “Learning to Fly.” But he also witnessed the darker periods in Petty’s life, and felt too powerless to intervene.

“We didn’t have touchy-feely talks,” Campbell said in a new interview with The Independent, reflecting on his relationship with his bandmate. “We’re dudes.”

That method of communication went beyond the music. When Petty began using heroin in the ’90s, Campbell refrained from addressing his concerns head-on — largely because he doubted he could make any difference.

“It would have gone like this,” he explained. “‘Tom, I’m worried about you. You’re hurting yourself. Maybe you ought to think about cleaning up.’ [Then] Tom would have said, ‘What the f— does Mike have to say about me? It’s my business. Leave me alone.'”

Added the guitarist, “You couldn’t talk Tom into anything.”

Campbell, who delves deeper into his experience with Petty in his upcoming memoir, Heartbreaker, made a similar point during a conversation with Guitar Player earlier this week.

“With Tom, it was like, ‘Your private life is yours, and mine is mine,'” he said. “‘I can see what you’re doing, but out of respect for you, I’ll trust you’ll do the right thing. If you need me, call me.'”

Petty died of an accidental drug overdose at 66 in 2017. After being found unresponsive at his Malibu home, he was taken to the hospital, where he died a few hours later.

His death came days after the iconic rocker completed a massive 40th-anniversary tour with his bandmates. At the time, Petty was struggling with a cracked and then broken hip, for which he was self-medicating.

When asked if he battles with guilt over the group’s decision to move forward with the tour despite Petty’s injury, Campbell told Guitar Player, “I don’t torture myself.”

Of Petty’s drug use, he said, “My conscious is clear because Tom knew that I knew, and Tom knew that I wasn’t forcing him and getting in his face about it. We had this invisible understanding, and I didn’t have to confront him for him to know how I felt about it.”

He added, “There was no second thoughts or reservations about going out on tour. In fact, the last conversation I had with Tom about it, I said, ‘Are you sure you want to do this? Are you up to it?’ He said, ‘I’m not staying home. I’m going out. I want to do it. If I have to be in a wheelchair, I’m going to do it.'”

Campbell recalled that their manager even proposed postponing the tour so Petty could get surgery for his hip immediately, but Petty resisted it. “Tom said, ‘I need to be out there. I want to play with the band, and we’re going to do it. I’ll be okay.’ So I have no second thoughts about it. I don’t beat myself up like that. I did all I could.”

Campbell’s new book, Heartbreaker: A Memoir, recounts his experience as the lead guitarist of Tom Petty and the Heartbreakers, from the band’s 1976 inception to Petty’s death in 2017. The book hits shelves on March 18.