All those years of rock-and-roll have started taking their toll on Brian May.

Months after being laid up with a knee transplant, the Queen guitarist has been sidelined with painful back problems.

May shared the news on his Twitter account, tweeting that he'd undergone an MRI that revealed "two torn discs, pressing on a nerve."

As the Daily Express reports, May sought medical treatment because he'd been "suffering agonizing pain in his buttock muscles" since playing at the iHeart Radio Music Festival in September.

Or as May put it in a Dec. 15 tweet, "I'm having a bad day. Knee pain now dwarfed by crippling pains in glutes, which I've had since Vegas iHeart. Then my iPhone died. Great."

May didn't share his doctor's recommended course of treatment for the injury, but in many cases, surgery is treated as a last resort for torn spinal discs -- instead, rest and specific exercises are used to heal the patient. For now, May sounds like he's just happy to know what was bothering him. "Well," he tweeted, "at least I know I wasn't imagining the pain now!"