An ailing Antonio Rogerio Nogueira (21-5 MMA, 4-2 UFC) has been forced to withdraw from this month’s UFC 161 event, and UFC officials are currently seeking a replacement opponent for Mauricio “Shogun” Rua (21-7 MMA, 5-5 UFC). The scratch was first reported by GloboEsporte.com , and MMAjunkie.com (www.mmajunkie.com) has since confirmed the change with multiple sources close to the promotion. GloboEsporte.com’s report cited a herniated disc as the reason for the withdrawal. A timetable for his return was not immediately established. Rua and Nogueira had been looking to renew a rivalry that began in 2005 when the two faced off in the quarterfinal round of PRIDE’s middleweight grand prix. In a fight that many news media outlets dubbed fight of the year, Rua earned a hard-fought unanimous decision victory. Rua went on to win the star-studded and historic 16-man tournament a few months later. The two fighters have seen mixed results in recent years