The Foo Fighters rocker invited his orthopedic surgeon, Dr. Lew C. Schon, onstage at Fenway Stadium Sunday during the band's second of two Boston sets, where the doc rocked out on a cover of The White Stripes' "Seven Nation Army."
"Holy s---, that's actually my doctor," Grohl, 46, told the crowd after the song. "What the f---? What a badass."
The former Nirvana rocker broke his leg during a tour stop in Sweden last month. The Foo Fighters postponed their tour so Grohl could undergo surgery on his fractured fibula, but returned to the stage for a show in Washington, D.C., on July 4 – and the frontman's been performing on a light-up throne ever since.
Nick Wass / AP