Ultimate Fighting Championship (UFC) will be on the hunt for a replacement to serve as the main event for The Ultimate Fighter (TUF) 17 Finale because flyweight champion Demetrious Johnson suffered an injury and will be unable to compete in his scheduled title defense against John Moraga on April 13, 2013.

Ariel Helwani confirmed on "UFC Tonight" on FUEL TV this evening that the 125-pound championship bout has been removed from the upcoming fight card in Las Vegas, Nevada. With the title fight scratched, it is unknown at this time which bout will replace Johnson vs. Moraga as the main event on the TUF 17 Finale.

Johnson (17-2-1) has been one of the most active fighters in the UFC of late, as the TUF 17 Finale would have been his fifth fight in 13 months. Perhaps the frequent fight schedule finally caught up to "Mighty Mouse," whose injury severity and possible timeframe for return are both unknown at this time.

The 26-year-old is coming off his first successful 125-pound title defense, a decision win over TUF 14 winner John Dodson at UFC on FOX 6 last January.

Moraga (13-1) challenging Johnson for the title was viewed as a surprise by most when the fight was first announced, but with an undefeated (2-0) record inside the Octagon and only one blemish on his record in 14 career mixed martial arts (MMA) fights, the 28-year-old was a worthy No. 1 contender.

TUF 17 Finale goes down April 13, 2013, in Las Vegas, Nevada. Also scheduled for the card is the second-ever women's UFC bout between Miesha Tate and Cat Zingano, as well as a Heavyweight contest that pits Travis Browne against Gabriel Gonzaga.