Michael Jai White ("Iceman" Chambers) stated that despite being on screen rivals, he and Scott Adkins (Boyka) got along very well off camera because neither of them were method actors. "On camera, we'd have on our mean faces and be trying to intimidate one another. But as soon as the director yelled 'Cut!', we were back to talking about places to eat good salads."
Scott Adkins had to put on a significant amount of weight for the part of Boyka in order to be visually convincing as a contender for Michael Jai White.
Scott Adkins said that the tricky part in playing Boyka, was doing the flips and rotations he already knew after putting on so much weight.
While the character George "Iceman" Chambers is the protagonist of this film, in the first "Undisputed" film, he was the antagonist.
Nu Image originally opposed Scott Adkins playing the role of the lead villain, which had been envisioned for a taller and heavier actor.