Florian (13-5) made the announcement on ESPN’s MMA Live on Friday.
The 34-year-old BJJ black belt has been considered one of the top lightweights for years, but after dropping two title shots and a title eliminator bout against undefeated Gray Maynard last August, Florian has decided he will give the UFC’s new 145-pound division a run.
“I didn’t really think about [changing weight classes] until the fight against Aldo was proposed at 155 and Jose didn’t take the fight. But I started thinking about it and people were telling me I could be able to get down to 145. I spoke to a few nutritionists that confirmed it and then made my decision based on that.”
Nunes (16-1), a 28-year-old Brazilian from Rio Grande do Sul, made his U.S. pro MMA debut in Dec. 2008 with a unanimous decision victory over Cole Province at WEC 37.
Following that, he scored a unanimous decision win over Rafael Dias at WEC 42 in Aug. 2009, but then lost a unanimous decision against L.C. Davis three months later at WEC 44. It remains his only loss.
Nunes made his Ultimate Fighting Championship debut at UFC 131 on Jan. 1 by handing former WEC featherweight champion Mike Thomas Brown his second straight loss.
A win for Florian or Nunes on June 11 could put either fighter very close to a shot at UFC featherweight champion Jose Aldo‘s title.
A heavyweight top-contender bout between “The Ultimate Fighter 13″ coaches Brock Lesnar and Junior dos Santos is expected to headline UFC 131. Also, heavyweight Dave “Pee Wee” Herman is expected to make his UFC debut on this card against Britain’s Rob “The Bear” Broughton.