I was thinking they were ambushed by a bunch of Romans 100 miles outside Rome, (probably 2 Predators in all), and they were taken down by the battle, but barely. Then the two of them,
or one Predator, have not decided, would be tied together while a bunch of Roman dudes in chariotes circle the arena, maybe throw some animals in there. Or the arena would be flooded, and the Predators would have to fight the Romans in the water, and try to cut themselves free before they drown.
Like I said its a concept.
ARNOLD23