I know players get tested for drugs with cocaine being a major issue in the professional game, but I gather the main purpose is to stop the use of performance enhancing drugs (steroids)

Anyway while my skill level will never surpass sunday league standards, a thought did strike me. I personally enjoy a little smoke before and after a match.

Is cannabis something that is tested for at the top level, and would it result in a ban?

It is definitely performance enhancing in my experience