Originally posted by crewl1 I would try f4/f5.6 if you want to have a better chance of catching the players and ball in focus.
I'll second this suggestion. The K-30 isn't great at tracking moving subjects, but with a narrower aperture, the AF just has to be close, not perfect. With telephoto compression, you don't have to worry about getting the foreground to stand out from the background, so even f8 isn't going to give you too much DOF. It's a long way to the other side of a soccer pitch.
You can gain 2-3 stops by dropping your shutter speed and increasing your ISO. ISO 3200 is not a problem with your K-30, you aren't looking for a high dynamic range and a little smoothing in post processing will only make the players and the ball look clearer and stand out more. In a pinch you can get by with 1/250 sec shutter speed, 1/320 will freeze footwork and player movement and a picture of a ball frozen in mid-air just looks weird and doesn't tell anything about the game action. The recommended 1/1000 sec (you used 1/800 for the posted picture) for shooting sports is a canard that drives me nuts, but there is nothing to stop you from doing your own experiment and proving me wrong.