is it sarcastic?

If the article is discussing a sporting event, "cop" is sarcastic.

Incidently I presume you mean "yard" rather than whatever "yuan" might be.

You missed the point altogether, Noddy. A fifty yuan "penalty" refers to a fine--yuan is the Chinese currency.

No, Alysa, the word is not sarcastic. At one time, policemen wore helmets with a badge on them, and the badge was made of copper. So people started to call them "Coppers," and finally, just cops. Here is an example of sarcasm:

I wish thousands more Chinese students would come here to ask what are often nearly incomprehensible questions.

Sentanta--

Thanks for the clarification. Now, back to the fray.

cop is also taken from constable on patrol

Oh! I thought it meant "can one pee?"