Well, real simple, the first one needs a little crop on the left, although this wouldn't have been a keeper for me because of the afore-mentioned ball blur and the fact the player's face can't be seen.
Second I wouldn't have kept either, too loose, blur in the bottom left, and some more blur.
For the third, again too much butt, not enough face.
I like the fourth but the image seems a little flat and a little oddly exposed, love the expression though!
Fifth is another one I wouldn't have saved, too loose, blurry, faceless, and ball, well, never mind, but it isn't conveying a story or message.
Sixth is nice, a little too early and loose (can't be managed obviously), and the SS was too low.
For the next game, you should try renting a 300 (f/4 or f/2.8, doesn't really matter for a day game, outside of size restrictions). It will give you very nice sharpness and constrast, plus 50mm more reach.
EDIT: Well, maybe that wasn't so simple, but...
