Cerrone and Guillard once trained together at Team Jackson-Winkeljohn in Albuquerque, N.M. During their stint at Jackson's the 155-pound title contenders became friends.
But that won't prevent them from going hard at one another on fight night.
"Two best friends fighting," Guillard said on Twitter. "We are about to kick each other in the face. Fun times, right!"
In 2011, each fighter was on the fast track toward a lightweight title shot. Losses, however, derailed their rapid climb to top-contender status.
Guillard was riding a five-fight win streak when he entered the Octagon against underdog Joe Lauzon on Oct. 8 at UFC 136.
An overly aggressive Guillard got caught in a rear-naked choke and tapped 47-seconds into the first round.
He would lose his next fight, via first-round rear-naked choke, to Jim Miller. That fight took place Jan. 20 in Nashville, Tenn.
Guillard (30-10-2, one no contest) ended his two-fight skid on July 7 with a unanimous decision over Fabricio Camoes.
Cerrone, a native of Colorado Springs, Colo., campaigned diligently to compete on the Aug. 11 card.
"Well, I sure wish someone would step up for Denver," Cerrone said Thursday on Twitter.
He was very active in 2011, competing in five fights. But he showed signs of fatigue during his Dec. 30 bout against Nate Diaz.
Cerrone lost by unanimous decision, ending his win streak at six.
In his most recent outing on May 15 in Fairfax, Va., Cerrone (18-4, one no contest) overwhelmed Jeremy Stephens en route to a unanimous decision.