Frankie Edgar will fill in for the injured Brian Ortega and fight Chan Sung Jung in the UFC Busan main event on Dec. 21, the promotion announced Thursday.

After failing multiple times to win UFC gold in the featherweight division, Edgar was scheduled to make his 135-pound debut against Cory Sandhagen at UFC Raleigh on Jan. 25. There is still hope that Edgar could stay booked for that fight, too, according to ESPN's Ariel Helwani, but the promotion and Edgar will have to reassess after the Jung fight.

Edgar, a former UFC lightweight champion, is coming off a title fight with champ Max Holloway in July. He lost by one-sided decision.

In his last fight, the "Korean Zombie" defeated Renato Moicano by knockout just over a minute into the first round of the UFC Greenville main event in June.

Ortega, who hasn't fought since December 2018, fell out of the Jung fight due to a torn ACL.

While Sandhagen might still get his chance to face off with Edgar, the 27-year-old bantamweight isn't happy with his opponent's decision:

Asked @cors_life how he felt about potentially losing the @FrankieEdgar fight next month. In short, he isn’t happy. Here’s what he said: pic.twitter.com/KQwCOKr3LT — Ariel Helwani (@arielhelwani) December 5, 2019

UFC Busan takes place at Sajik Arena in Busan, South Korea and also features a light heavyweight bout between Volkan Oezdemir and Aleksandar Rakic.