Billie Joe Armstrong's Rehab May Force Green Day Show Cancellations

Billie Joe Armstrong isn't ready to hit the road again. 

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The Green Day singer, in rehab for substance abuse, may not be available to resume his pop-punk frontman duties for the next month or two, judging from comments made by the band's long-time producer Rob Cavallo.

"His doctors are still evaluating," said Cavallo to Rolling Stone. "All I can say is I don't know if we'll see him before or after Christmas. It's basically undetermined when he'll be back." 

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Armstrong was checked into rehab in late September shortly after he abruptly ended his set at the iHeartRadio festival by smashing his guitar and exclaiming "I'm not f--king Justin Bieber." He said at the time he was protesting that his set was cut short by organizers. 

STORY: Green Day Bassist: Workload Forced Singer Billie Joe Armstrong's Into Rehab

On BBC radio this week, bassist Mike Dirnt pointed to the tour schedule as weighing on Armstrong. "We hadn't slept in forever, and Billie had definitely had the worst of it," Dirnt said. "He'd been going through his own struggles."

The band's latest three albums (¡Uno!, ¡Dos!, ¡Tré!) are all scheduled for release in relatively quick succession. (¡Uno! debuted at No. 2 on the Billboard 200 in September with 139,000 albums sold, ¡Dos! will debut on Nov. 13 and ¡Tré! arrives on Jan. 15.)

Green Day is currently scheduled to go on a tour of the West coast of the U.S. beginning on Nov. 26, including seven shows before Christmas.