Bellator lightweight champion Brent Primus confirmed Wednesday he withdrew from his title defense against Michael Chandler on April 13 at Bellator 197.
Primus is dealing with a knee injury, sources told MMA Fighting's Ariel Helwani.
Chandler (17-4), who's coming off a win over Goiti Yamauchi in January, will now face Brandon Girtz in the main event, Bellator announced.
Girtz (15-7) most recently defeated Luka Jelcic in December, snapping a three-fight losing streak.
Chandler, the former champion, lost his lightweight belt to Primus last June, suffering a first-round leg injury that stopped him from continuing the bout. It isn't known how long Primus, who has yet to defend his title, will take to return.