A STEP version can be found here:
http://students.autodesk.com/?nd=kit...r=& x=30&y=17
You will have to use the pull down menu to select the right model. Select: "2013" AND "Competition Field STEP". The Pick "Go".
The model is not assembled correctly. It is a STEP file, so it comes in unconstrained. If you carefully re-constrain it, you can get a model that matches the Game manual.