Green Day's epic weekend -- which started with a tantrum-marred set at the iHeartRadio Festival and ended with frontman Billie Joe Armstrong checking into rehab -- may have come as a shock to fans, but according to the latest rumors, it was probably inevitable.

A columnist for the Chicago Sun-Times cites "sources close to the band" in a report offering behind-the-scenes details of what transpired following Armstrong's profanity-laden rant at the festival, which concluded with him smashing a guitar onstage before stalking off -- reportedly due to a set countdown clock that expired faster than Armstrong would have liked.

According to the report, Armstrong's bandmates Mike Dirnt and Tre Cool were part of an intervention that convinced him he needed to seek help for what is being referred to as "abuse of various substances, including both prescription drugs and alcohol." The column went on to quote a "Green Day insider" as saying, "Billie Joe has been a loose cannon for a long time. It’s long past time when he should be getting some serious help."

All this drama comes at an inopportune time for the band, which is ramping up for the release of three new albums over the next several months, in addition to a major worldwide tour. Here's hoping Armstrong finds the time and care he needs to get healthy again.