When Roper is watching the soap opera, and throws the ring away to watch his entourage chase it, it clearly falls out of the box as it skips on the floor. Yet, when Rollo puts it on, before Roper takes it, he takes it out of the box.
The length of Roper's cigarette just before the fight.
Since the beginning of the film Roper is clearly not in the physical shape an experienced professional heavyweight boxer has to be in.