BJ Penn will return to the UFC in 2014 to face a familiar opponent at an unfamiliar weight.
UFC officials announced Wednesday that Penn has agreed to coach the 19th season of "The Ultimate Fighter" reality series opposite Frankie Edgar. The series is scheduled to debut in January.
The two coaches will meet at the conclusion of the season in a 145-pound contest. Edgar (16-4-1) is 2-0 against Penn at 155 pounds. He won the UFC lightweight title in April 2010 over Penn, then beat him in an immediate rematch four months later. Both victories came via unanimous decision.
Penn (16-9-2) hasn't fought since a lopsided decision loss to Rory MacDonald last December. A former UFC champion at lightweight and welterweight, Penn is 1-4-1 in his last six fights. He has never competed in the 145-pound weight class.
"BJ really hates the fact that he lost to Frankie Edgar," UFC president Dana White said in a released statement. "It's something that's been burning deep inside of him for three years now.
"He's moving down to 145 to not only avenge those defeats, but to try and become the first fighter in UFC history to win titles in three different weight classes."
It will mark the second time Penn, 34, has served as a TUF coach. In 2007, he coached opposite Jens Pulver in the show's fifth season.
Edgar will look to catapult himself back into title contention in the trilogy bout with Penn. The New Jersey native is 1-1 since dropping to 145 pounds this year, including a unanimous decision loss to champion Jose Aldo in his debut at UFC 156.