Krassimira Stoyanova has canceled her upcoming performances of Verdi’s “Don Carlo.”

The Royal Opera House announced that due to illness the Bulgarian soprano had to withdraw from singing the role of Elizabeth of Valois.

American soprano Kristin Lewis will now take over the run making her Royal Opera House Covent Garden debut. The soprano has been in demand for the past few years and recently sung the roles of Amelia in “Un Ballo in Maschera” and “Aida” for Vienna State Opera, Leonora in “Il Trovatore” and Mimì in Puccini’s “La Bohème” for La Fenice, Venice, and Bess in Gershwin’s “Porgy and Bess” for La Scala, Milan.

The cancellation marks the fourth straight withdrawal at the Royal Opera House. Last week Dinara Alieva canceled her engagements in Puccini’s “Turandot” while Rolando Villazon canceled Donizetti’s “L’Elisir d’Amore.” Meanwhile, Anett Fritsch withdrew from Mozart’s “Mitridate.”

“Don Carlo” is set to star Bryan Hymel, Ludovic Tezier, Ekaterina Semenchuk, Paata Burchuladze, Andrea Mastroni and Ildar Abdrazkov. The revival opens on May 12 and will be conducted by Bertrand de Billy.