Credit: Kevin Mazur/WireImage

Dave Grohl’s doctor proved he can rock as hard as the Foo Fighters during Sunday night’s show at Fenway Park. Dr. Lew C. Schon, an orthopedic surgeon who performed surgery on Grohl’s leg after he broke it from falling off a Swedish stage last month, joined the band to perform a cover of the White Stripes’ “Seven Nation Army.”

“Holy sh-t, that’s actually my doctor,” Grohl said to the audience. “What a badass.” Dr. Schon sang lead vocals on the track, as the rest of the band supported him.

After Grohl broke his leg, the Foo Fighters’ tour was postponed, but the injured Grohl has been performing from a giant light-up throne that he says he dreamt of when he was high on pain meds related to the incident. “The idea of the throne is just f–king ridiculous, especially for a band that has never relied on any kind of production at all,” he told EW in a recent interview.

The tour resumed over Fourth of July weekend, and since then, Grohl said these are some of the best shows the band has ever done. “We talk about this after every show in the dressing room,” he said. “What seemed like some sort of set back at the time has turned into this beautiful blessing in disguise, where this throne and these crutches and these audiences make us play longer and harder than we ever have. It’s this whole new energy in the show.”

See some fan-shot footage of Dr. Schon’s performance.