There are 3 ways of extracting/cutting parts of images which have a non-uniform border.
They are -
1)Using the Lasso Tool
2)Using the
Pen Tool
3)Using the Extraction filter
In this tutorial, you'll learn how to make a cut using the Pen tool.
Made this tutorial with soccer cut-outs in mind -
http://learning-photoshop.com/select...-pen-tool.html
Hope the tutorial helps. Comments here as well as on the site are much appreciated.
PS : I've been working on this site for around a month now, and I'm thinking of adding a section dedicated to Soccer Tutorials - if you've made a soccer related tutorial, and want it published on the site, PM me as soon as possible.