The former governor will participate in Saturday's evening performance of "Rod Blagojevich Superstar," his spokesman Glenn Selig said Tuesday.
The show is a takeoff on the rock opera "Jesus Christ Superstar" and follows Blagojevich's rise and fall. Its run was supposed to end June 14, but the improvisational comedy group extended performances to Aug. 9 because of its popularity.
Selig declined to say how much Blagojevich will be paid, but said he will make a donation to Gilda's Club, a cancer support organization founded by Gilda Radner, the late "Saturday Night Live" performer and Second City alumna.
"The play is a satire and he plans to watch it along with everyone else and expects to get a good laugh and at the same time help Gilda's Club," Selig said.
A Second City spokeswoman did not immediately return a message from The Associated Press. A woman who answered the telephone at the box office but declined to give her name said Saturday's first performance was sold out, but tickets were available for the later show.
Blagojevich has pleaded not guilty to charges that he schemed to sell or trade President Barack Obama's former U.S. Senate seat and used the muscle of the governor's office to get campaign donations. He was impeached and ousted from office in January.