A statement released by the Covent Garden venue said that Keen would take on the role of Molina in Manuel Puig's prison play "due to the indisposition of" actor Glen.
Keen (The Changeling, Tom and Viv and the title role in Pericles) will join Rupert Evans (Romeo and Juliet and King John) in the production, which opens April 25 following previews that begin April 19.
Set in a South American jail cell, the play by late Argentine dramatist Puig (1932–1990), focuses on two cell mates; Marxist rebel Valentin (Evans), punished for his ideals, and romantic fantasist Molina, convicted for his sexuality.
Piug's play is best known as the 1985 movie starring Raul Julia and William Hurt, and as a musical by Kander and Ebb.
Directed by Charlotte Westenra (Darfur – How Long is Never), the Donmar version features a new translation by Allan Baker. For more on Kiss of the Spider Woman, which will run until May 26, call (0)870 060 6624.