The Ultimate Fighting Championship on Saturday will return to the UFC Apex in Las Vegas with a respectable slate of prelims, and while it may be lacking in immediate relevance, the UFC on ESPN 34 undercard figures to offer some entertainment value. Heavyweights are set to take center stage. Devin Clark and William Knight leave their familiar haunts at 205 pounds to move up a division for a short-notice affair in the featured slot, but viral sensation Chris Barnett should generate the most buzz against a disappointingly normal opponent in Martin Buday.