Though the cast has seen plenty of famous faces during its 12-year run, they couldn't help but be "starstruck" by the Oscar winner, actress Sarah Drew said.
Drew, who plays Dr. April Kepner, told ABC News, "He's a powerhouse, and it was really exciting to get the chance and opportunity to work with him," adding that she and her colleagues were initially intimidated by Washington.
But Washington ended up being pretty easygoing as a director, according to Drew's co-star Jason George.
George, a.k.a. Dr. Ben Warren, said, "[H]e shows up and he's just a funny, great guy and a really great director. And it was reassuring to be like, okay, he puts you at ease, and that was great."
"Grey's Anatomy" airs Thursdays at 8 p.m. ET on ABC.