Several sources have told Yahoo Sports that popular referee John McCarthy will receive an official's license from the Nevada Athletic Commission and be assigned to work at UFC 178 at the MGM Grand Garden in Las Vegas on Sept. 27.

The card, which will be headlined by a flyweight title bout between champion Demetrious Johnson and challenger Chris Cariaso, will be the first McCarthy has worked in the "Fight Capital of the World," since 2007.

McCarthy, who along with Herb Dean is considered one of mixed martial arts' two finest referees, announced a brief retirement after working a show at the Palms in Las Vegas on Dec. 8, 2007, to take a broadcast position with The Fight Network.

He returned to officiating in November 2008, though he did color analysis for several MMA cards. But he ran afoul of Keith Kizer, the former executive director of Nevada commission, after making comments Kizer felt were unfair and overly critical.

Nevada, though, has been seeking to improve the quality of its refereeing and judging in both MMA and boxing since several controversies late last year. Those controversies got the attention of powerful politicians such as Gov. Brian Sandoval (R-Nev) and Sen. Harry Reid (D-Nev). McCarthy began officiating at UFC 2.

McCarthy is expected to be granted a license at the commission meeting on Aug. 21 in Las Vegas, though it could extend until the first meeting in September. It is unclear which bouts at UFC 178 that McCarthy will work.

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