The search for the next crop of “The Ultimate Fighter” contestants begins begins next month with one major catch: Hopefuls must hold undefeated professional records. The casting call for “The Ultimate Fighter 27: Battle of the Undefeated” is for male fighters only who compete at featherweight (145 pounds), lightweight (155) and welterweight (170). As history has shown, though, there are no guarantees of which weight classes or class will end up on the show. The tryouts will be held Dec. 12 at Palace Station Hotel & Casino in Las Vegas, and they begin at 8 a.m. PT. The undefeated fighters who wish to participate need to have at least three fights as a pro. The show begins taping in January 2018 and will air on FS1 later in the year.Candidates must be aged 21 to 34. They need to fill out an application (available atUFC.com) and bring it to the tryouts. The fighters will grapple and hit pads, and must bring appropriate gear. If selected to continue the casting process past the first day, fighters will need to be prepared to remain in Las Vegas until Dec. 16. “TUF” is currently airing its 26th domestic edition.The Ultimate Fighter 26: A New World Championfeatures 16 competitors angling for an opportunity to become the inaugural UFC women’s flyweight champion. The two teams have been led by former UFC champion Eddie Alvarez and ex-WSOF champ Justin Gaethje. TUF debuted in 2005 and has launched the careers of hundreds of current and past UFC fighters. Its also produced champions in Forrest Griffin, Rashad Evans, Michael Bisping, Matt Serra, T.J. Dillashaw, and Carla Esparza.For more on the UFCs upcoming schedule, check out theUFC Rumorssection of the site.