[wulf]

Are your cameras more to the point and shoot end of thing than being DSLRs? I'm not enough of a gearhead to be sure but suspect that is the case. Such cameras can produce excellent results but, principally due to the smaller sensors they use, tend to provide a much wider depth of field than a DSLR would.

In many cases that is a good thing - if you just want snapshots of your family, for instance, it makes it much more likely that you will get a usable result. However, you have to work harder to get narrow DoF effects.

I would suggest learning what you can do with the cameras away from the sports pitch. It will be things like setting the aperture as wide open as possible, zooming in on the subject and finding an angle where the subject is a good distance away from the background. Master this in a static setting and you will have a better idea of if it is possible to get the sports pictures you want (allowing for the fact that the players won't be stopping to pose!).

Wulf