Billie Joe Armstrong won’t be taking rehab “lightly” according to his bandmate Mike Dirnt.

After an on-stage outburst in Las Vegas last month, where the Green Day frontman smashed his guitar during a foul-mouthed rant, the singer announced he would be seeking help for substance abuse.

The band - which consists of bassist Mike, singer Billie Joe, drummer Tré Cool and guitarist Jason White - have had to postpone upcoming shows, which Mike says has been difficult for them.

“Billie doesn’t take things lightly and he wouldn’t take rehab lightly, either,” Mike told the latest edition of Kerrang!

“He’s in the middle of some really big things, but we’re going to pull through. It’s killing everyone – Green Day has never been a band that sits still, but sometimes you have to step back and let life go on rather than try to control everything.”

The band had been proving their hard-working attitude by promoting three new albums during their world tour.

The hectic schedule is thought to have contributed to Billie Joe’s breakdown and Mike says the most important thing right now is his bandmate’s health.

“I know that my friend’s life is in danger and that’s all I care about,” he explained.

“We’re brothers-in-arms waiting for Billie to return healthy, but we’re not going to force anything. Tré and I will be standing here for Billie.”