Date, site change for Sonnen-Silva

— -- A fight between light heavyweights  Chael Sonnen and Wanderlei Silva will headline a televised UFC event on May 31 in Brazil.

The bout was originally announced as the co-main event for a UFC 173 pay-per-view card on May 24 in Las Vegas. UFC officials announced the switch Thursday.

Sonnen and Silva will soon wrap up filming in Brazil for "The Ultimate Fighter: Brazil" reality series. They have been serving as opposing coaches.

Sonnen (28-14-1) is coming off a first-round TKO loss to Rashad Evans at UFC 167 in November. The 36-year-old former middleweight reportedly offered to step in on short notice against Daniel Cormier next week at UFC 170, but the UFC declined.

Silva (35-12-1) has not fought since March, when he beat  Brian Stann via second-round TKO in Saitama, Japan. The former Pride middleweight champion has alternated wins and losses in his past six fights.