SI: Your character is a composite of Bannister's several coaches. How did you approach the part?
Plummer: I watched film on Franz Stampfl [Bannister's coach when he broke the four-minute mile in 1954, pictured below with Bannister]. And the writer [SI's Frank Deford] did enormous research on the language coaches use when speaking to runners.
SI: How familiar were you with Bannister's story?
Plummer: My wife saw him win that race. I lived in England in the swinging 1960s. It was after Hillary and Everest. Then came Bannister. We were all cognizant of his rise to fame.
SI: What are the origins of your lifelong affair with tennis?
Plummer: I've played since I was five. I play singles, but it will be doubles soon; it's getting a bit dodgy out there.
SI: Is Roger Federer worthy of a stage production?
Plummer: Federer is almost too perfect to be dramatic. I compare him to Manolete, the bullfighter who achieved such perfection that the Spanish found him dull.
SI: What about McEnroe: The Play?
Plummer: His story might repel audiences. They would leave in droves [laughs]. He's great now: He has a sense of humor about himself and is a wonderful commentator.