The withdrawal leaves Luiz Cane temporarily without an opponent.
According to a source with knowledge of the situation, Vemola was recently diagnosed with a serious infection that has left him unable to train. Faced with the issue, he was forced to pull out of the fight.
The 25-year-old is 8-1 overall and most recently won his light-heavyweight debut with a first-round TKO over Seth Petruzelli. Prior to that, he'd lost a unanimous decision to Jon Madsen before deciding to shift to a lower weight class.
The UFC will have about a month to find a replacement for Vemola, as UFC 128 takes place on March 19 in Newark, New Jersey.
Cane is 10-3 with one no contest in his career after dropping two straight bouts.
He's fallen in back-to-back TKO's at the hands of Antonio Rogerio Nogueira and Cyrille Diabate, respectively.
UFC 128 will feature a light-heavyweight championship main event pitting title holder Mauricio "Shogun" Rua vs. phenom Jon Jones.
The Vemola-Cane fight had been expected to air on the Spike-televised preliminary card.