Met conductor James Levine. (Josh Reynolds/AP)

On the day of his scheduled return to the Metropolitan Opera to begin rehearsals for the coming season after several months’ absence from the podium, conductor James Levine instead announced that he has undergone yet another emergency back surgery last week and is canceling all of his fall performances.

Bowing to the inevitable, the Metropolitan Opera on Tuesday named Fabio Luisi as principal conductor, effective immediately. Luisi will take over Levine’s scheduled fall performances at the Met, including the new productions of “Don Giovanni” (Oct. 13) and “Siegfried” (Oct. 27), the latest installment in the Met’s new Ring cycle directed by Robert Lepage. Levine will remain the company’s titular music director.

The news is not altogether surprising, given that Levine’s ill-health — he suffers from spinal stenosis — has been playing havoc with his performing schedule for some time. In March, he stepped down from his position as music director of the Boston Symphony Orchestra as of this fall, and subsequently canceled all of his summer performances to give himself time to recover.

Levine’s doctors said he was recovering successfully from his last back surgeries, in May and July, when he fell while on vacation in Vermont and injured one of his vertebrae, necessitating yet another operation last Thursday, according to the news release.

Luisi has been rumored for some time to being groomed as Levine’s successor; he was appointed as the Met’s principal guest conductor in April, and he had already taken over a number of Levine’s previously canceled performances this spring. He has conducted frequently at the Met since making his debut there in 2005 with Verdi’s “Don Carlo,” and he was already scheduled to conduct the new production of “Manon” in March 2012.

Fabio Luisi was named the Met’s principal conductor, effective immediately. (AP Photo/Metropolitan Opera, Cory Weaver/ASSOCIATED PRESS)

Luisi canceled a number of engagements, including appearances with the Rome Opera and the San Francisco Symphony, to clear his fall calendar. He does not, however, currently have another music director position. In 2007, he took over as music director of the Dresden Staatskapelle and Semperoper, one of the leading orchestras and opera houses in Europe, but a dispute with the orchestra led him to resign in 2010, before the end of his contract.

Levine hopes to return to the Met in January for the premiere of “Goetterdaemmerung,” and is still scheduled to lead the complete Ring cycles in April and May.

Read more classical music coverage on Anne Midgette’s blog, Classical Beat.