My guess would be that Burkhead/ Okafor will split reps behind Helu, similarly to the way Helu/ Castille split reps behind Lucky during their freshman year. Given Okafor's size and performance in the spring game, I would think he would be the likely candidate for the majority of short yardage carries.
I guess we really won't know until FAU rolls into town. As if we nedded more question marks on the offensive side of the ball......... <_<