At a rehearsal one recent afternoon, the Metropolitan Opera Orchestra was roaring out the final scene of Wagner’s “Der Fliegende Holländer” (“The Flying Dutchman”), which opens on Monday, the first new Met production of the work in over 30 years.

A man’s shadow, projected onto a screen at the back of the stage, stood several stories high behind the action. Watching it, it was hard not to think of another giant looming over this production, even in absentia: the commanding Welsh bass-baritone Bryn Terfel, who had been scheduled to return to the Met for the first time in eight years to sing the title role in Wagner’s early, torrid Romantic masterpiece.

Then, late in January, while appearing as the Dutchman in Spain, Mr. Terfel fell and fractured his ankle.

“Unfortunately I’ve been around long enough that I’m used to calls like that,” Peter Gelb, the Met’s general manager, recalled with a rueful chuckle.