I usually start with the 70-200, but then put on a 1.4 convertor. It's mostly out of laziness, I don't have to move so often to keep the action in range. With the 300 you'll can spend more time behind the goal having the action coming towards (or away) from you, but I think i'd prefer to be using a zoom. When the pass is thrown, you've a chance of zooming out and getting onto the receiver before the ball arrives.
Anyway, the game lasts long enough to try a few different things. I'll be at two games, back to back, on Sunday.
There are some examples of things that work, and probably things that don't, on my website.