"Mighty Mouse" injured and out of April 13th bout
Ariel Helwani announced the news during Tuesday's edition of UFC Tonight.
Moraga will not receive a new opponent. Rather the fight will be delayed to a later date.
Johnson is coming off his five round decision victory over John Dodson at UFC on FOX 6 this past January 26th, while Moraga last fought and defeated Chris Cariaso at UFC 155, bringing his win streak to 7.
No announcement has been made as to when the fight will be rescheduled, however a new main event for the TUF 17 has been announced as Urijah Faber vs. Scott Jorgensen.