Thanks for the comments.
I got the lonnnnnnng lens out for the day: 105 to 300mm (that would be about 150 - 450 mm on a 35mm camera), and sat behind the posts, so I could get the action wherever it was (except behind heads and goal posts!!).
For the fellow snappers - the camera was set on 400ASA, 'A' (apperture priority) set to about f4.5, white balance changed to 'sunny day', and let the camera take care of the rest.
"
It was almost too easy...." (Garth: Waynes World)
Older and Evil-er but none the wiser 