John McTiernan recycled the players, disguising their faces with elaborate costumes and helmets for each away game. With each new game they improved and worked better as teams.
At the beginning of the first Rollerball match after Aurora mocks Jonathan, There is a cable attached to her motorcycle that is visible when she does a 180 burn out.
When Jonathan is beating several guards to death with the rollerball it can be clearly seen that he is hitting them with the palm of his hand, not the ball.
Alexis Petrovich: You see Yevgeny over there, so full of himself now. He used to work in the post office. I introduced him to the proper financing, and now he owns the mines. Yeah, making a fortune. Keeps the miners in line. Good business. You might wonder why I'm not in it myself. I don't need to own the mines, Jonathan. Do you know why? Because I own the man who owns the mines. All he has, I have. Same with the supermarkets, the TV station, locomotive plant. I don't need a political position, because I own the men who do.