Half-Pint Imitation Is Put on the Brink

“Never having a real speaking role before, I’ve been having to work on my, you know, my enunciation, my articulation, things like that,” said 27-year-old Matthew Risch, the luckiest ex-understudy in New York City. It was the last day of November, and he was sitting in front of a bulb-lined mirror in his new dressing room at the Roundabout Theatre’s Studio 54.

Nine days earlier, the actor Christian Hoff, 13 years Mr. Risch’s senior and poised for a breakthrough as the star of the retooled Rodgers and Hart mega-musical Pal Joey, injured his foot during a performance, according to an announcement issued by the theater. It was during a Friday night show, one week into previews.

“That’s why I almost threw up when they told me,” said Mr. Risch. “It wasn’t because of joy or nerves; it was because I felt so completely horrible for him, because he had been nothing but the most generous person I’ve ever had the chance to work with. I’ve understudied before, but I’ve never understudied a role of this magnitude. And he, from day one, came up to me and was like, ‘Anything you need.’”

The morning after Mr. Hoff’s mishap, his understudy was called in for a rehearsal as Joey Evans, the sleazy nightclub cad, a character Brooks Atkinson called “a rat infested with termites” when the show debuted, starring Gene Kelly, in 1940. And that night, Mr. Risch played the part for the first time in front of a paying audience. “It was a very frightening experience, but, my God,” he said, “it was exhilarating.” He was given the role for good the next day.

A week later, 15 minutes before a physical therapist was due to work on his hip, and an hour and a half before Sunday’s preview matinee, it was raining. Mr. Risch shuffled around the dressing room he had inherited from Mr. Hoff, wearing green-striped socks with pink toes and heels, jeans and a soft V-neck sweater that showed chest hair. His shelves had been stocked with two bottles of Cetaphil, Kiehl’s Facial Fuel, Tiger Balm (“which saves my life”), Simply Saline nasal spray (“also saves my life”), Red Cross table salt for gargling, Rosebud Salve, Axe deodorant, Brylcreem, two bottles of CVS brand hair gel and two bottles of Paul Mitchell spray. “I try and keep my hair in place as much as I can,” he explained. Nevertheless, he tends to pull at the pompadour-size tuft of hair that falls over his forehead and down to his massive, ready-for-close-up black eyebrows.

THE UNDERSTUDY'S TRIUMPH is practically the oldest story in show business. There’s the young Miss Harrington, triumphing (onstage, at least) over Margo Channing in All About Eve, of course. In real life, Catherine Zeta-Jones got her break when the star and the star’s understudy both fell ill for a performance of 42nd Street, which itself is about a star breaking her ankle on opening night. “All my friends have been reminding me that this happened to Shirley MacLaine back in the day, when she went on for … I should know this … Hold on, I have it right here somewhere,” Mr. Risch said, checking his iPhone. “Was it Can-Can or something? It was one of those oldies. … But anyway she got injured—oh, Pajama Game, it was Pajama Game—and there’s a story she was literally about to hand in her notice to quit and she got to the theater, and they were like, ‘Where have you been? You’re on!’ And she quickly put away her notice, went onstage, the producers were there, they offered her the part, and the rest is history.”

In Rosemary’s Baby, Mia Farrow’s horrifying husband, played by John Cassavetes, gets a big part because his competition is mysteriously blinded. Do understudies—unconsciously even—wish evil on the leads? “No! I hope not. I certainly didn’t,” Mr. Risch said. “And I don’t think—the good people don’t. I consider myself a good person; I would never wish harm on anybody ever. I believe in karma.”

Bob Fosse understudied for Harold Lang’s Joey during the long-running early-’50s revival, but never got on. In another revival 11 years later, Fosse finally got the lead role, plus a Tony nomination.

“I had been very back and forth,” Mr. Risch said, “with, ‘Am I going to go on?’ ‘Oh, I bet I’ll go on.’ ‘Oh, I don’t know if I’m going to go on.’ Christian is a very consummate performer, and I knew because it was a limited engagement, I was like, ‘Oh, I don’t know if I’ll ever get a chance to go on.’ But, you know, I knew his wife was pregnant, so I was like, ‘Maybe she’ll go into labor early and I’ll get to go onstage!’”

Mr. Hoff couldn’t be reached for comment.

“I sent him an email on Thanksgiving,” his former understudy said, “and I haven’t heard from him, but I know he’s healing and doing well and with his family.”

MR. RISCH GREW UP in Massachusetts. “I had the best childhood. Oh my God, I had a great childhood, absolutely. It was fantastic,” he said. He went to the artsy Tower School in Marblehead until ninth grade, where he was excused from gym because of his theater work. “I would have had to do sports, and it freaked the fuck out of me. It really scared me. I had a huge fear of sports and jocks. I was bullied as a kid by Marblehead local kids every once in a while—Chris something, Sadulski? Asshole.”