It's been a rather tumultuous year for AC/DC, and it just got even more complicated with the recent arrest of drummer Phil Rudd. During a new interview with USA Today, AC/DC's Angus Young and Cliff Williams reveal that their issues with Rudd actually preceded his recent arrest.

Rudd was initially charged earlier this month on a murder-for-hire charge, as well as 'threatening to kill,' plus possession of methamphetamine and marijuana. While the murder-for-hire charge was dropped, the other charges remain.

Bassist Cliff Williams states in the interview that the band's troubles with Rudd have been going on for a while, explaining that the drummer was not himself when it came time to record their new album, 'Rock or Bust.' "It was tough to get [him] there in the first place," said Williams, while Young added, "It put us in a difficult situation. It put us in a spot where we couldn't move forward. Does the guy show up? Is he reliable to do his job in good shape? We've always been a solid reliable unit."

In the end, Rudd did complete his drum tracks for the upcoming AC/DC album 'Rock or Bust,' which is due on Dec. 2. But his involvement with the band moving forward remains a mystery. He's already missed a photo shoot as well as the band's recent video shoots.

"Phil created his own situation," says Angus Young. "It's a hard thing to say about the guy. He's a great drummer, and he's done a lot of stuff for us. But he seems to have let himself go. He's not the Phil we've known from the past."

The guitarist adds that the alleged drug usage implied by the recent charges may have something to do with that, adding, "When you get in that land, it's very hard … I don't know the exact situation … I can only say, from our perspective, that guy needs to sort himself out."

Shortly after Rudd's arrest was made public, the band issued a statement that they intended to proceed with the release of their new album and would tour in 2015. Frontman Brian Johnson later reiterated those sentiments, revealing that the band would "absolutely" tour next year.

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