Yesterday it was confirmed that Antonio Rogerio Nogueira was out of his co-main event bout against Mauricio Rua at UFC 161 on June 15th. Chael Sonnen went to Twitter later that evening to volunteer his services on short notice. According to Globo's Ivan Raupp, who originally reported Lil Nog's back injury, Sonnen will indeed be taking on Shogun in 12 days time:
Incredibly, Sonnen (27-13-1) almost became the LHW champion of the world in April against Jon Jones, but that's only because Jones broke his toe and would've lost had he not finished Chael in an otherwise lopsided 1st round. There was talk of Sonnen possibly fighting Wanderlei Silva next, but that appears to be off the table for now.
If this report is true, it very much changes the fight plan for Shogun, as Sonnen is one of the best MMA wrestlers in the UFC. Given Shogun's top 10 ranking, it could also be a potential path for Sonnen to eke into the top 10 (should he win, of course) and hang around as a perceived title contender at 205 lbs.
Bloody Elbow will provide updates on a potential Sonnen/Rua fight as more information becomes available.