Middleweights Constantinos Philippou and Nick Ring will take the place of a light heavyweight contest between Cyrille Diabate and Chad Griggs on the UFC 154 main card.
Philippou and Ring will now be part of the pay-per-view telecast from Montreal on November 17.
Georges St-Pierre and Carlos Condit meet in the main event for the unified UFC welterweight title.
Fans have been pushing for Philippou and Ring to join the main card, as the two have a combined 7-2 record inside the Octagon. Philippou is 11-2 overall, including four UFC victories, while Ring is 13-1.
Diabate and Griggs will now be part of the FX prelim lineup.