Nice shots. It seems as though the focus is centered at their ankles. Not quite sure but the focus seems to be off slightly or maybe it's just my eyes.
i like the first one. lots of action and weird poses. my only gripe would be that 2 and 3 seem to aimed a bit low. i would put the ball more along the 25-33% height line instead of 50% like it is here.
if u dont mind me asking, what settings did u use and what kinda 70-300 lens?
i agree that a bit of PP would help but these are jpeg straight out the camera.
Its a 70-300 Nikon VR F4.5. As far as settings go i used the widest aperture as it was a bit o cast. Mostly shot at 1/1000th and i was using the higest iso. Perhaps i could have got away with a lower shutter and lower iso but i doubt if i could have freezed the action. But this was mu first ever sports attempt