Rosen joins a cast that currently includes Jonathan Hadary as King Arthur and Hannah Waddingham as The Lady of the Lake with "American Idol" finalist Clay Aiken, Tom Deckman, Rick Holmes, David Hibbard and Bradley Dean.
Rosen, who is a co-creator of Don't Quit Your Night Job, was most recently seen on Broadway in The Farnsworth Invention.
Spamalot features a book and lyrics by Eric Idle, music by John Du Prez and Eric Idle, direction by Mike Nichols, choreography by Casey Nicholaw and is based on the screenplay of "Monty Python and the Holy Grail" by Monty Python creators Graham Chapman, John Cleese, Terry Gilliam, Eric Idle, Terry Jones and Michael Palin.
The musical tells the tale of King Arthur and his Knights of the Round Table on their quest from God for the Holy Grail — with a short stop in the dazzling Spam-filled land of Camelot.
Spamalot earned the 2005 Tony Award for Best Musical and took home honors for direction (Mike Nichols) and one of its stars (Sara Ramirez).
Spamalot celebrated its third anniversary on Broadway March 18. On Broadway Spamalot plays Tuesday-Friday at 8 PM, Saturday at 2 and 8 PM and Sunday at 2 and 7 PM.
For more information visit www.montypythonsspamalot.com.