Back KOs Antonio Rogerio Nogueira

Light heavyweight contender Antonio Rogerio Nogueira suffered a back injury that has forced him out of a June 15 bout with Mauricio Rua at UFC 161 in Winnipeg, Manitoba, a source close to the situation confirmed Sunday.

Brazil-based website Combate.com reported Nogueira's injury and withdrawal earlier Sunday.

Nogueira and Rua were scheduled to fight in the co-main event in what would have been their second meeting. Rua defeated Nogueira by unanimous decision on June 26, 2005, during a Pride FC bout.

Nogueira-Rua II is the second high-profile bout to fall off the UFC 161 card. Interim bantamweight titleholder Renan Barao, who was slated to defend against Eddie Wineland, withdrew after tearing ligaments in his foot.

Nogueira, the eighth-ranked light heavyweight by ESPN.com, was seeking to extend his win streak to three. In his most recent fight, Feb. 2 at UFC 156, Nogueira (21-5) scored a unanimous decision over Rashad Evans.

Rua lost by unanimous decision to Alexander Gustafsson in December. The former UFC light heavyweight champion is ranked 10th by ESPN.com and has a pro record of 21-7.

UFC officials are in the process of finding a new opponent for Rua.

A light heavyweight fight between Evans and Dan Henderson is slated to headline UFC 161.