UFC's former lightweight champions Frankie Edgar and BJ Penn will face off in the main event of The Ultimate Fighter (TUF) 19 happening on July 6 at the Mandalay Bay Events Center in Las Vegas, according to MMA Junkie.

The upcoming event marks the third time the two fighters will face off inside the Octagon. Penn first fought Edgar in UFC 112 on April 10 of 2010, to defend his UFC lightweight title. He lost the championship via unanimous decision which broke his eight-year undefeated streak fighting under the lightweight division.

On his first title defense in UFC 118 held in August of the same year, Edgar fought Penn in a rematch. The judges awarded the fight to Edgar via unanimous decision.  

Currently, Penn and Edgar are the respective coaches of the middleweight and light heavyweight fighters of TUF 19. The 19th season of the mixed martial arts-themed reality show is set to air on Fox Sports 1 on April of this year.

The TUF 19 Finale will take place a day after UFC 175. This is the first time in UFC history that two consecutive events will be held in the same venue. This is all part of the company's "International Fight Week", a promotional event that also features the UFC Fan Expo.   

According to a press release on UFC's website, "Several of the hottest locations in Las Vegas will host UFC themed events and fans will have access to UFC stars and celebrities. The UFC Fan Expo will also return with new activities, youth and adult, grappling and martial arts tournaments, fan contests, live performances showcasing Las Vegas talent, more main stage activities, and exciting experiences for fans to interact with fighters. Other fan favorite activities will return including a pool party with Octagon Girls, training sessions with fighters, a free concert, weigh-ins and more."