The UFC's "Primetime" series returns Friday with a three-part special for UFC 146: Dos Santos vs. Mir. UFC heavyweight champion Junior dos Santos and challenger and former champion Frank Mir will be the focus of a three-part "UFC Primetime" special for their main event. The two fight May 26 at UFC 146 at the MGM Grand Garden Arena in Las Vegas. After the first episode airs, the FX cable network will air the second and third parts on the next two Fridays leading into the event. The first episode will airs Friday at 11 p.m. Eastern, immediately following "The Ultimate Fighter LIVE" on FX. The second and third episodes will air in the same time period on May 18 and May 25, with the conclusion of the three-part special airing the night before dos Santos and Mir fight. Additionally, replays of the episodes will air on Fuel TV as well as select Fox Sports affiliates across the country. The path to the UFC 146 main event has been an interesting one, to say the least. Dos Santos, who won the belt from Cain Velasquez in November, was expected to meet former Strikeforce heavyweight champion Alistair Overeem in his first defense. Overeem beat former champion Brock Lesnar in December in a top contenders bout to earn a shot at the title. But at a March news conference to promote the all-heavyweights main card of UFC 146, Overeem and the five other fighters on the dais at the event were given surprise random drug tests by the Nevada State Athletic Commission. Overeem was the only one of the six who didn't pass, getting red-flagged for an elevated testosterone-to-epitestosterone level that reportedly was 14:1. The NSAC standard is 6:1. Overeem was scheduled for a hearing with the NSAC on April 24 where the commission would decide whether or not to grant him a license to fight, despite the elevated levels – pending his explanation. But on the Friday before his hearing, UFC president Dana White announced that Overeem had been pulled from the main event and Mir would get the title shot. Mir had been scheduled for a co-main event top contenders fight with Velasquez on the same card. So dos Santos went from preparing for a standup specialist in Overeem, perhaps the heavyweight division's best striker, to preparing for arguably the best ground fighter in heavyweight history in Mir. And Mir went from a three-round fight to a five-round title fight with a month's notice.READ MORE CLICK HERE