The 62-year-old actor's starring in the show isn't a typical return after a few years' hiatus. Predominantly a film actor, Williams hasn't starred in a TV series since the finale of the sci-fi sitcom Mork & Mindy over three decades ago.
"The show is Robin Williams on television. That's all you need to know; that's the show," Gellar praised of her co-star's long awaited return to the small screen.
Veteran actor Michael J. Fox is also making his anticipated return to television this upcoming fall season. With a decade-plus series TV hiatus since he starred on Spin City, Fox makes his comeback in the self-titled The Michael J. Fox Show.